I Keep Growing Bigger Boobs

So, this has taken me a long time to post... I've been here for a while now, but it's taken so long to get the courage to post something, but here goes.

I am 15 at the moment and have very big boobs, they just kinda stared to grown when I was 10 and have not stopped. To be honest, I do not mind, I like them being big, they're fun and I think I look pretty good with them (but clothes are hard to find that fit and look good). But what I want to know is, why do people feel like they have to be so mean to me because of them? Why go and put effort into trying to hurt someone just because they don't feel like they "should" or "have to" have surgery just to match someone else's idea of pretty? I mean, I have never heard of smaller busted women being told in public (I've had people shout it at me across a street) they they "should" have implants?

A lot of people tell me it's just jealousy, but I have never seen anyone come up to one of my friends and tell her that she should change herself in any way (and she is SOOO pretty), so why is it just us busty people who get it? And why is it that I get it more the bigger I grow?