Or despite more to the point, stress relief. Stop and ask yourself these questions:
1. Have you ever purchased one of those cheesy stress relief toys from a local Spencers, or other novelty shop? You know the ones. They're often shaped like a human and are squishy, or painted with a target, or make annoying repetitive sounds designed to make you want to scream at them. You are mean to heap upon them as much abuse as you can dish out, and they'll keep coming back for more.
2. Have you ever found yourself playing a violent game like Unreal Tournament, or any "street fighter" type game, and realized that being your opponent (s) senseless makes you feel a bit bit less like choking someone for real?
3. Have you ever looked up the omnipotent, immortal cheat codes for your favorite RPG video game, and used them to cast the most devastating "town killer" type spells through the entire game, for no reason other than the enjoyment of watching those little buggers die?
Now, ask yourself: Have you ever logged in to a MU * you knew offered nothing more than run-of-the-mill, generally stock hack n 'slash, and found yourself spending hours running around typing "KILL (insert generic monster name here) ", and actually enjoying it?
There's a certain flavor of fun to be had smashing NPCs to pieces. Heck, there's even a nice adrenaline rush in besting another player (though, the few & far between but wildly PK-only games). But best of all, there can be a wonderful release of stress in conquering virtual foes. It's the same underwriting motivation and relief that drive people to kick-boxing for stress management, or to punching their pillows, or to buying those novelty stress toys and riddling each other with bullets in UT.
Do not believe me? Give it a try. Keep an open mind. Train your character a bit, get some good weapons, and go hunting. See if you do not feel the stress melt away with each level you gain!