from the time i was born to about 15 i was a very social outgoing person then i became very shy and depressed idk brain chemistry

A lot can actually happen in that time and it effects people in different ways and stages .I have never been fully confident but when I was younger I did afew silly things and did actually talk a lot more to people until I was bullied at the badest point and kept everything bottled inside and among other things .it was like I had a wave just knock all my confidence out of me I don't trust many people and so on it can happen if you don't wanna believe it don't but it can happen .

maybe something happened. maybe around people that hurt them and they become closed off.

They peaked too early.

Once you reach your own personal pinnacle your only choices are stay right there or go back downhill.

doesn't htat happen a lot?

because we change

we become careful/paranoid from ignorant and irresponsible