Why can't I get off on top?

Why can't I get off on top? It's supposed to be easier for females to cum on top right? My friends tell me about how being on top is their favorite position and some even say they can only get off on top. What the heck? I literally feel it going in and out that's it. No pain but no pleasure either. If im on top I'm in control so why isn't it pleasurable? Help! Maybe I'm riding completely wrong? Tips please