What exactly is "amount comfortable to them?" I'm sure if you sign up for the reserves you're going to be ok to be called upon if needed? Since I think that's t

What exactly is "amount comfortable to them?" I'm sure if you sign up for the reserves you're going to be ok to be called upon if needed? Since I think that's the whole point? I know a reservist that got deployed for several months, so it isn't like it isn't heard of.