Ever since I started masterbating when I was younger I realize how strange of a habit I picked up along the way. During masterbation I lock my knees up and it seems make it more pleasurable, but now it seems like if I don't do it than it's not that great at all. As if I'm bored of it or what? Anyone else think this is stupid? I do, and that sucks ass. I also have been getting EXTREMELY chronic headaches in the event of all this, I've read over other posts and apparently the knee thing doesn't have anything to do with it. But as far as the headache goes, it still hurts.