You're wrong about that. It's not extraordinary at all. The look out for creepy old(er) men starts young. It's actually fairly ubiquitous. I was 11. My daughter was 10. My sister was 12. My best friend was 10. This girl was 9.

The real reason girls mature faster than boys is this. We have to. Because as soon as you get near puberty you will attract the predatory gaze of creepy old men if you are even the slightest bit attractive. The more attractive you are the more of them there are. Given the opportunity, many of them will act upon that desire. They are not just window shopping.

As a girl you simply can't afford the innocent naivety of youth as long as boys can.