US Army 1983-93 -- mostly as a 11B Infantryman, and about half of that Airborne. Medically retired at 100%. My hair's still military short, I'm as fit as I can manage to be, which is nowhere as much as I'd like to be. I still miss the Army -- I wanted to join since I was a kid, and fought to avoid being retired out. (Figured I could at least do paperwork or something!) Though I think that Bush's invasion of Iraq is probably the absolutely stupidest thing any American president has ever done, I'd still rather be there than here on the sidelines. I can understand how Prince Harry feels...there's a lot of reasons why a person enlists, but you actually fight for your buddies.
That said, no one should be ashamed if they haven't served -- not everyone is cut out for military service. Everyone has their strengths and weaknesses. My brother is regarded as one of the best legal researchers in the Southwest US, he's in charge of everyone at his firm except the lawyers themselves, and his boss pays him enough and gives him enough benefits that he's sliding into the lower levels of the upper class. He's not cut out to be military -- but he should be damn proud of his accomplishments. (I can't convince him of that, however!)
Civilians can't understand what it is like to be military -- it's not that they are bad, they just don't have any frame of reference. I can't really understand the kinship my mother feels with fellow Holocaust survivors -- it's the same thing. I don't have the frame of reference to even begin to imagine what she survived. It does anger me when civvies criticise the military for who they are, though -- they're blabbering about something they know nothing about, while acting like they actually do know what they're talking about. You just have to think of them as you would any other know-nothing, and go on.