Scott, there are many former marines. There is only one "Ex-Marine" however(Lee Harvey Oswald.) Former Marine is the term used to describe anyone who got out of the corps. Ask any marine buddys you might have. As far as why didn't I go Marine reserve, the answer is that they are even more underfunded than the Active Duty Marine Corps, and they still try to be hard asses like they're active duty(at least from the few I've met.) The guard is more laid back(almost disgustingly so at times, but thats just the jarhead in me,) has better funding(at least up in Oregon,) and plus I automatically became a state resident by joining the guard up here, because they are funded by the state, thus dramatically reducing my college tuition costs.
Besides, you'd be amazed how many former marines are in the guard. It's like coming home(wipes tear from corner of his eye.)
Nate