Self-Esteem is Overrated
I firmly believe that the whole "self-esteem" thing is vastly overrated. It seems like our culture is starting to eschew fair praise and deserved reward in favor of "self-esteem". Excessive emphasis on self-esteem, I think, prevents real problems from being solved and devalues actual achievement.
A little self-confidence is a good thing. You can't get ahead in life if you don't have any of it, and people who have it are much more pleasant and uplifting to be around. But there's a difference between self-confidence and self-esteem. Self-confidence is believing that you're a worthwhile human being. Self-esteem is believing that you're spectacular. All it is is a politically correct term for an inflated ego.
I have no self-esteem, and I don't see that as a problem. I'm just willing to acknowledge my many, many, many flaws, and do something to change them. I suck at math; so, I'm getting tutoring in SAT math and working out of a book to enhance my skills. I'm a fat cow. Thus, I'm dieting. If I had self-esteem, I would believe that I was gorgeous, funny, smart, and desirable, despite the obvious fact that none of the above are true.
In Decidius Erasmus' work The Praise of Folly, the allegorical character Folly praises people who believe they have talents, abilities, and traits that they don't actually posess, because it makes them happy. Indeed, such is a great existential question: is it better to delude oneself into a pleasant falsity, or accept an unpleasant reality? I vote for the second option... but that's just me.