Why are guys all jerks?

I have some stuff to say bout this. I so agree with the whole they are after one thing, but not all guys are jerks. A lot of them are, but I mean.. girls can be pretty jerk-ish too. I have had experience with the whole ‘once they get what they want the leave and forget you exist’ and to be honest I am still not over the guy who did it to me. I have liked him for 5 years now, and I am very much so in love with him. I find it hard to get over him. We have had a thing off and on for bout a year and a half, but I will not have sex with him, because I know I will become even more attached.. but I guess what I am trying to say is that you can’t just give them what they want because most of the time they will say, yea I had sex with her. blah blah blah… and they will brag about it, and then forget it. Then there you are sitting there like, did it mean anything to you other then ‘oh yeq we had sex?” and the answer is no. Boys are very immature until high school is out.. because testosterone and what not. So when in a relationship, dont fall in love to quickly, and keep you head straight with what YOU want. if you dont wanna have sex then say no, and if he doesnt care, and keeps asking you.. then you need to really think about if he is right for you or not.. hope this helps…