Nobody ever get tired of talking about sex? We sure think about it a lot. We watch people do it a lot on tv and in the movies. We buy all kinds of products and services in the hopes we'll be having sex a lot. And all the magazines tell us we SHOULD be having sex a lot. But that doesn't mean we actually know much about it. Remember, thinking about something doesn't make you an expert! But to help you on your way, we present 23 things you most likely didn't know about sex.