People always go for the most appealing things. What's appealing to them gives confidence. And what gives you confidence matters a lot in boosting once self-confidence. It really does not matter how poor a person is or how handsome a person is. Self-esteem is what people have for themselves, the inner respect for oneself. And if you don't respect yourself, one can't expect others to respect you.

There might certainly be mood swings. Some bad critics and you feel bad. Good critics on the other hand boost your confidence, sometimes beyond what actually should be such that it turns into ego. Striking a balance between them is critical in the sense that you neither lose your heart for bad or some time fake critics and keep your head on your shoulders for good critics.

Well when it comes to the point of asking oneself - How good is your self-esteem? It really doesn't mean how great you respect yourself, rather it means how good is one's attitude. At the end of the day, it is that attitude that decides one's fate.