if that's what you want to do, then go for it, and don't let anyone else talk you out because they're only thinking of themselves. think about your future at the same time. try and join and go into an area that you can use after the military. example, if you want to be an aircraft mechanic, sign up for that. don't sign up to be a GI. or if you want to be a police officer, be an MP. not an engineer.
i wanted to join the military, but it won't really help me in my career. so that would a waste of 2+years. but oh well.