My self esteem never came from compliments or other people's opinions. It came from personal successes. Especially from times that I didn't think I could do something, but put in my best effort anyway and was able to get it done. It came from building up skills that most people never knew I had because you don't go around doing those things and even if people know you can they don't understand how difficult it is or how much work went into it.

And so many times I would overhear people saying that I have unearned confidence. People who always quit as soon as something becomes difficult, and never even attempt things they aren't sure they can do.

Don't be like that. Don't be jealous of other people's confidence, you just end up being bitter and wasting your time trying to tear down others instead of improving yourself.