I don't know why some people have it and some don't. I don't know why many people don't find it until they are adults, but some have it practically from birth. I think part of it must be genetic, part of it must be related to temperament, and much of it must be related to how one is raised. Three of my kids are very confident (although one of them definitely derives most of his confidence from his experience with NCFCA - public speaking). My girls are both uber-confident. Over the weekend, Therese went to a dance and she had a terrific time. She went by herself (no date, no friends) and she just strode into the venue like she owned it. My friend later confirmed to me that she never sat down once. She danced every dance. I saw the pictures last night; she definitely had a blast. She told me that she got asked to dance and she was surprised - she "forgot that was a thing." She was flattered, but she had more fun just dancing in a group with her friends. She's done the couple thing, but she's enjoying the single thing *so* much more. I'm happy for her. It's funny, for her *not* being in a relationship has given her far more confidence than being in one ever did. Everyone is so different. I look back on my own teen life and wonder how it would have been different if I had not been in a serious relationship with the same boy throughout all of high school - if I had been more confident.
Whatever the case, I am delighted when I look at my own kids, especially my girls. I'll be honest, I think homeschooling has everything to do with how confident they are. They don't have to face the daily beat down that is public school (although I actually think they would handle that okay). They can thrive at home and in their extracurriculars. Again, let me emphasize for those who think it is important - they have both faced significant challenges. They have both been bullied. They have both been passed over when they should have been chosen. They have both suffered. They are not growing up in a bubble - far from it. Like I always say, I am a mom who homeschools, not a homeschooling mom. There's a big difference.
I am going to ponder this idea of confidence more. I think it's really important, especially for teen girls.