As a practice, I try my best to admit when I am wrong and apologize for my transgressions because it's simply the right thing to do. Pride can get us into a lot of trouble these days, and it's never truly worth it. However, given the complex world around us and the many people for who we can simply never please, there are some things that I will personally never apologize for, and neither should you.
1. NEVER APOLOGIZE FOR TAKING CARE OF YOURSELF

Depending on our chosen profession in life or where we find ourselves in relation to others, it can feel conflicting to take time for ourselves, buy things for ourselves, even show up for ourselves. I am here to tell you that the line between selfishness and altruism can sometimes be razor-thin. The truth is, we are all selfish to some degree. Whether you think that it is right or wrong is irrelevant. It is what it is, and in my opinion, we ought to be selfish up to a certain point.
We cannot take care of anyone else until we learn to take care of ourselves. One of the most fulfilling things that we can do in life is to find ways to add value to others. Guess what? That selfless mindset is, in and of itself, selfish! That shot of serotonin and oxytocin that we get when we do things for others and feel further connected to them is something that we receive and enjoy for ourselves, and that's a good thing! It is life's way of propelling us to do good for others.
But never apologize for showing up for yourself because you deserve it. You have purpose, meaning, and worth. Demonstrate this by taking care of yourself. This creates the necessary synergy in our lives to continue giving to others after adequately giving to ourselves. It's all about balance, however. Try your best not to lean too much in one direction.
2. NEVER APOLOGIZE FOR YOUR PERSONAL SUCCESSES

This one is a doozy... especially in today's world. Everyone's metric for success is different, whether it be money, comfortability, peace of mind, more time, any combination of these things, or perhaps none of them at all, but instead something different. The common ingredient for any form of success in life is hard work and perseverance in the face of adversity. The best things in life are those we must work for because it makes our journey to achieve what we desire in life well worth it.
Our successes are difficult to manifest, and sometimes they take great sacrifice to achieve over potentially extended periods. No self-respecting person should apologize for the success that they have garnered. If you have a dream and work hard to achieve it, don't sell yourself short or diminish your accomplishments. If it is important to you and not destructive to yourself or others in nature, then relish in what you have accomplished. If you've acquired success honestly and fairly (deep down, you will know this to be true, even if others don't), then never apologize for that.
3. NEVER APOLOGIZE FOR BEING INQUISITIVE

If you have a question, then ask it! Will it sound dumb? Perhaps... it depends on the question and the setting, but if you don't know something, the quickest way to figure it out is by being upfront about your uncertainty.
I wish I could tell you that everyone would be glad that you asked about something you didn't understand. Sadly, many people get comfortable knowing what they know and forget what it was once like not to understand a particular subject, task, or concept. Still, ask the questions you need to have answered, and don't be afraid to do so.
Depending on what it is you have questions about, chances are that others have had those very same inquiries, and you aren't alone in your confusion. If you happen to be the only one who genuinely doesn't know (trust me, I have been there), then don't ever be sorry for that.
4. NEVER APOLOGIZE FOR HAVING A QUESTIONING ATTITUDE

This one is near and dear to my heart. I have some issues with ceding to authority, and believe it or not; they got worse as I continued with my time in the military. Leadership guru John C. Maxwell says that "the leader makes the position, the position does not make the leader." This is so very true, even in places like the military, where rank is so vital to the hierarchal structure and order of the organization. The point is that even great leaders need to be questioned now and again.
If an idea is poor, then call it out, especially if it has the potential to negatively affect others or risk total failure of your organization's primary objectives. We have to be willing to take some heat in life to do what is right, and any leader or manager who is worth their salt will be glad that you could provide some forceful backup (even if they aren't willing to admit so).
Never apologize or be afraid to question a plan, idea, or action. History is rife with examples of how a little bit of forceful backup and a questioning attitude saved time, money, resources, and even lives. Have the courage to be one such person and never feel bad about it because the alternative is feeling worse living with the regret of not calling something into question when you very well could have.
5. NEVER APOLOGIZE FOR WHAT YOU BELIEVE IN

Our personal beliefs and convictions are important. As previously stated, when cultivating relationships with others, the objective in life should never be to appease everyone but rather to find people who believe and value the same as we do. For some, it can be easier than others, but if you think a certain way, whether it is a particular religious persuasion or a general set of values and principles that guide you through life, never feel that you must apologize for those beliefs.
DO NOT shove them down other people's throats in an attempt to force them to see the world as you do (no one likes that). Instead, live your life in a manner that does not detract or diminish from other people's lives. More importantly, find the people who see the world as you do and cling to them.
6. NEVER APOLOGIZE FOR YOUR DREAMS

We all have hopes, dreams, aspirations, and a vision of our place in the world that makes us feel our best. The key to understanding those dreams is to recognize that everyone has them, regardless of how simple or exquisite they may be. For some, achieving these dreams is more complex than for others, but they exist nonetheless. Never apologize for what you want for yourself or the people for whom you love. It is YOUR life, and only you can control what you do in this world, and more importantly, how you react to it.
History is replete with naysayers who tried to stand in the way of other people achieving what they see for themselves in their mind's eye when they lay their heads to rest each night. But as I have stated before, the best things in life are those we must work tirelessly to acquire. If you have a dream to do something, be a part of something, or become something, only you can ever know what it means to achieve it for yourself, and you should never apologize for what it means to you and for wanting to accomplish it in the first place.
7. NEVER APOLOGIZE FOR DEFENDING YOURSELF

Never accept disrespect. We don't need to fixate on "getting even" in life or fighting "fire with fire." I believe that we should turn the other cheek as often as we can in an attempt to seek the higher path. However, don't take abuse from people and allow yourself to become (or remain) their personal punching bag, no matter where you find yourself. There are ultimately two types of people in this world: those who let life push them around and those who don't.
Seek the truth, always, and do your best to deliver it when you can. Hold others accountable and set the record straight as often as possible because your reputation may very well be on the line, but always defend yourself. Though it is certainly cynical to say, it is undoubtedly true that there are nasty people out there that will take whatever they can and as much as they can from you. Please don't give them the satisfaction of doing so.
8. NEVER APOLOGIZE FOR BEING DISCIPLINED

If you are working hard to achieve something and other people try to diminish your efforts because they feel insecure about themselves, don't apologize. An excellent example of this is when we politely turn down an offer to eat something that doesn't help us achieve the goal of losing the weight we want. As polite as it may be to accept the offer, other people aren't the ones seeking our fitness and nutrition goals, and thus they will never be the ones to accept the consequences (good or bad).
This is an overly simplistic example, but the idea is the same for many aspects of life. Don't let people pressure you to do certain things. If you have particular goals or ideas in mind for yourself, say NO and do so warmly, then move on. Those who don't respect it don't respect YOU, and I would argue that they don't have much of a place in your life, plain and simple.
People who achieved greatness in this world never did so by pandering to others and letting people decide what was best for them. Again, there are two types of people in this world, and trust me when I tell you that those who allow life to push them around never truly unlocked their full potential nor had the life they truly wanted.
Having the discipline to become what we want to be in this world takes some grit and when other people witness it, it can cause them to feel insecure about themselves. The truth is, their insecurities shouldn't be allowed to affect your trajectory in life. So don't let it slow you down.
9. NEVER APOLOGIZE FOR "CLEANING HOUSE"

As I have stated numerous times, not everyone needs to be in our lives. Knowing when to cut these people out is seldom easy to do. Still, when we learn to recognize the difference between those who add value to our lives and those who subtract value, it gets easier with time and becomes more and more necessary if we want to achieve the life we seek.
I have said it before and shall repeat it: give to givers, and we will find the fulfillment that we desire, but give to takers, and they will take all that they can from us. Knowing when to distance ourselves from the toxic people in our lives (a.k.a. "cleaning house") helps us to mitigate dysfunctional experiences so that we can better have our needs met in the long run. In doing so, you will find that your productivity and overall happiness will increase.
10. NEVER APOLOGIZE FOR ESTABLISHING BOUNDARIES

There is tremendous power in saying NO. We must learn to say NO to the things in life that we don't want in order to better say YES to the things in life that we do want. Boundaries must be established virtually everywhere, whether at work, at home, with friends, family, and even lovers.
How we view our worth is tied to the boundaries we set for ourselves in life. Additionally, how we seek the approval and validation of others is showcased by the lines in the sand that we draw out and the ones that we do not.
If we show up for ourselves and demonstrate self-respect, then we will take measures in order to stand our ground and call out behaviors or remarks towards us that we do not tolerate or accept.
Set boundaries for yourself in life so that you can choose to be happier, and never apologize for it.
11. NEVER APOLOGIZE FOR WHO YOU LOVE

Life is funny. We make plans for ourselves and think that we sometimes have it all figured out, then life introduces a few surprises, and for some of us, there may be more than others.
One such surprise is who steals our hearts. I have seen relationships that ended because people cared too much about what others thought of who they loved. We sometimes feel pressured by society to think or act a certain way, or sometimes we grow up believing in this "image" of the kind of person with whom we will spend the rest of our lives; putting pressure on ourselves.
For so long, I was one such person, and I recall ending more than one relationship because I didn't open my mind or heart to the possibilities which love sometimes can afford us, and in doing so, I hurt some pretty great women.
Would I have married them? Perhaps not, but now I suppose I'll never know, and I, like so many people, focus on what we think we want, so much that we deprive ourselves of the love which we have the potential to give.
I believe that love is the most powerful force on earth; because for love, we will climb the tallest of peeks, cross the most treacherous of terrains, and endure some of the worst pain imaginable. We ought to enjoy and cherish what love can offer us because it is beautiful and powerful.
Never apologize for WHO you love, and if you love them, do so with all you have and be willing to learn and grow from the experience, however long it may last. More importantly, don't give a damn what others say. Give and learn to receive the gift of love when you can.
CLOSING THOUGHTS
Life is hard enough, on its own terms. Nobody ever got anywhere they truly wanted to be by letting life push them around. Do not ever apologize for anything that I have mentioned above. So long as you live in a dignified manner, respecting those around you and their right to pursue their own paths in life, you will find happiness and fulfillment, guaranteed.
The 5 Levels of Leadership by John C. Maxwell
The 5 Love Languages by Gary Chapman
You Are Good Enough by Dr. Robert J. Furey
No More Mr. Nice Guy by Dr. Robert Glover
WORKS CITED
Maxwell, John C. The 5 Levels of Leadership: Proven Steps to Maximise Your Potential. Center Street, 2021.
Glover, Robert A. No More Mr. Nice Guy: A Proven Plan for Getting What You Want in Love, Sex, and Life. Running Press, 2017.