Could this have been what led to my shyness?

I've been really shy for the majority of my life (I'm now 21). Well back in I think kindergarten, I had been into power rangers, as was my friend. Well we were all outside for recess and my 'friend' and a couple other kids I knew came up to me and told me to go fake punch this other kid, because he wanted to play power rangers. So I did that, and everybody just started laughing. Teachers and all. It kind of feels like when I go anywhere in public, I feel paranoid like everyone's watching me and laughing to themselves. Could that have been one of those traumatic moments that may have caused me to become so shy? If so, what can I do about it?