I'm not attracted to girls my own age?

I'm 16, male, and I used to get crushes on girls, the usual. But then I went to this work thing, and got some flirting with this woman who turned out to be 23! (I apparantly look like I'm in my 20's, she's not a pedophile). Nothing came of it, and now I simply am not attracted to girls my age. They seem to childlike, and it does nothing for me. Whats up with me?