I've always been a big gamer. I've had almost all the console systems from the Atari 2600 onward. Currently I only lack a PS3. I've played a lot of the massive multi player online games on the computer and I was addicted, actually addicted to a few of them.
You know you're addicted to a game when it's all you can think of. You're going to work and the only thing on your mind is the new armor you got last night and how you just can't wait to get home to go raiding in that new dungeon. You know you're addicted when all you dream of is the game you're playing. You know you're addicted when you happily forgo almost all real life activities so you can play one single game 60 to 80 hours a week, every week for months or years.
Just like all addictions you'll try to rationalize you're game playing when someone confronts you about it. You're saving money, you don't like going outside, other people watch TV and you play the game instead, you're an introvert, this is the way you relieve stress, you'll quit when you get to level 60, no wait, it's level 70 now. Maybe you'll just play a little while longer until you've gotten into a big guild, explored all the dungeons, and gotten a whole set of epics then you'll quit. Oh no, they just came out with another expansion and all your gear is crap, you don't want to quit when just anyone can easily go and get better gear than you have, of yeah they raised the level cap again and when you quit you need to retire at the top.
Then one day several years down the road when the game is winding down and everyone is migrating to the new game on the horizon you look back over your gaming career and see all those missed days of work, those missed relationships, those missed days out in the sun. You realize that you're different than you were before you started playing this game. You're out of shape, you've gained a lot of weight, you're skin is pasty, your mind is in a fog and look at those dark circles under your eyes from all those nights you stayed up until 5am raiding. And what do you have to show for it? a few high level pixels that aren't worth anything. But you saved so much money from not going out to the movies, or out to eat, or the bar, or on vacation, right? Probably not, as you played the game you probably stopped progressing at work, if you could, you probably cut your hours back to the base minimum you could still work and survive so you had more time to play your game. No money made here.
At least that was my experience. I played 4 1/2 years of EQ and retired from that game in 2004 with several high level characters with somewhere around 320 days played. That's 320x24 hours = 7,200 hours played on EQ. I retired from WoW a couple of months ago with a lvl 70 priest with all epics, a lvl 63 shaman, and several twink characters ranging from 19, 29, and 49. I had played 2 years of WoW and had around 120 days played between all those characters. When I look back on it now, I'm afraid it looks like a lot of wasted time.