Correct. I'm 18 and male. That's also possible that might be the reason. Granted I do look a little bit younger than my age.
I checked your profile and it says you're male. That may very well have something to do with it. I'm female, young (22), and look even younger.
Furthermore I'm pretty sure the guy who harassed me today was also hitting on me. My mom says if a guy talks to me just because he wants to, he's hitting on me. It's disgusting because a lot of them are my dad's age.
One good thing is my dad gave me permission to give them HIS number if they ask for mine. XD I'm still waiting for the opportunity though.