It's so true. One day, I just went onto the site I modded on for three years. One day, I just sat down, took a look at the place for a few minutes, and then sent a PM to the admin. "Yeah, I don't want to moderate anymore..."
Never went back since. It wasn't even a small forum either. It had about five thousand or so members, and I knew a good chunk of them personally, having met them in person over the years. It wasn't even that bad of a place; there was no "unmod" or equivalent, and for the most part, the membership was fairly decent. It just got to the point where I was tired of telling the same people to shut up, moving threads, fixing goof-ups, and having to babysit a bunch of random names on a screen. I just didn't want to do it anymore.
So yeah, I can completely understand why DarkeSword would just quit. Good for him. Modding can suck the life out of you. Hopefully he'll take some time, relax, do what he has to do, and maybe, just maybe, he'll come back, but as a regular member, and not have to deal with any of the stuff that made him leave.
You're welcome back anytime you want DS.