Why am I not sexually attracted to boys my age?

Nope, you just like older guys, full stop. Don't let others guide you to think it's a flaw in your character. It's perfectly natural. Everyone leads their life the way in which it suits them best and not their friends or the 'norm' as some might call it. If you like older guys, explore and enjoy them but of course expect people to grunt here and there. It's your life at the end of any day. :)