The limitless process of challenging everything in your life, makes you think. You have been hard wired to make some choices without thinking about them. This is not your fault. Since an early age, you observed certain behavior that you copied. As the normal example of how to act, you accepted it without question. At this stage in your life, you can use logic to evaluate your automatic actions/reactions. Once examined, you can choose to keep or discard them. If you are aware of an automatic response that is not improving your life and may in fact be causing problems, you can change it.
Take a simple case of reacting to someone making a comment that is designed to make you feel bad about yourself. You have a choice to accept what is being said or reject it because in your heart you know it is not true. In this case, people will make negative comments about you or your life. That is a reality. If you accept those comments without question, your self esteem may wither away.
You have to consider that people make comment about others for a variety of reasons. It may be to make themselves feel better about their own life. The comment may be made simply because they are in a bad mood at that moment. The point is that you have the choice of accepting or rejecting what other say. It is important to learn about yourself. Something to remember is that you need enjoy your own company. Liking yourself and enjoying your own company gives you freedom and strength.
Strength comes from knowing yourself and your core beliefs. When you know yourself, comments from others can be received with a reasonable perspective.
Consider that you have been working for a year to get in shape when someone comments that you look fat. Based on the mental work you have completed, the effect of such a comment is minimal. You like yourself and the way you look. They may have any number of reasons for their comment. You have the choice to consider or discard it. The effect of that comment is therefore minimal rather than devastating.
Everyone is looking for a method to improve their life and find the key to a happy existence.