Let us think of past and present leaders. It is apparent that each famous leader is a person of strong character. Over one's lifetime, character has to be developed painstakingly. It is strength of character that makes a person truly great.
What is character? It means that you operate from a base of integrity, which means that you operate within your moral code, even when no one is watching you or there to reward you. It means that fear and guilt are temporary and occasional visitors to your life who simply appear to help you make amends when necessary but don't stay long. It means that you have nothing to hide, which in turn gives you the freedom to achieve success to its fullest.
Some people call this the "golden rule," whereby they treat others as they would want to be treated. Every day, you have a chance (or more than one) to practice this rule for yourself. For example, if at work you are tempted to steal credit for someone else's idea so that you're the one who receives the promotion, this is at best a hollow victory and not really yours. Rather, practicing the golden rule means giving credit where credit is due -- and that means taking it (with modesty) when it's yours as well. Only then will the goals you reach be truly yours and be worth your pride. On the other hand, if you step on people to get where you're going, you can only expect that the same is going to happen to you by others. In short, you get what you give.
For a better life, try treating people as you want to be treated. Treat them with respect, honesty and courtesy. Appropriate anger is okay, but losing your temper is not. Of course, most of us have at one time or another regretted losing our temper or something similar in a situation, but this happens...