Talk to fifteen high schoolers, and ask them if they think high school is easy. Then in a couple years look back and see if high school really was that difficult.

Of course everything seems harder while you're going through it. That would apply to relationships (or lack thereof), prison, school, training, etc. Looking back on Basic Training, it was harder than hell to go through, but I could definitely do it again. And probably be better going through it. And the people I know that had gone to and been out of prison, they said it was nothing. Even the two people I knew that were in prison when I last heard from 'em, they said it was pretty easy.

Even if it's nothing they'd ever want to do again...it must not be enough of a deterrent if they keep doing stuff that'll get 'em sent back.

And countries with public executions and extremely strict, even abusive, prisons...they don't have much for crime.