I think we're talking about a bunch of different things here. Self-esteem is not the same as assertiveness. In fact some of the most assertive people I know are actually very insecure on the inside. Similarly, you can be very timid and introverted but still be comfortable with and accepting of who you are on the inside. In my book, that's what good self-esteem means: accepting yourself as a worthy human being, regardless of whether you're outwardly assertive or have an introverted/extroverted personality.

I don't think my low self-esteem shows to most people. I've never let fear get in the way of my goals, and I've achieved most of what I set out to do. I'm a very stubborn person and I almost never give up. But none of that changes the fundamental self-hatred that I have, and the inability to allow myself to be happy or to fathom that anyone could genuinely love me or want me around. Any attempt to change that just makes me feel like I'm lying to myself because I'm too weak to deal with the truth, which is even more pathetic. So, the more I try to get rid of the self-hatred and try to accept myself, the more I despise myself for it.

I think people are born with a predisposition towards an introverted or extroverted personality (or any kind of mix), and different personalities will show good self-esteem in different ways. But nobody is born with self-hatred; that takes a lot of long and hard work by those who are meant to love and protect you.