If you have never tried a game such as WoW or Camelot it can be hard to understand. It can consume your life. I know marriages that were ruined because of online gaming addiction, jobs lost, new romances started that ended badly, etc... Crazy stuff but that is how the games are designed. They require a huge investment of time to achieve a level of efficiency. That keeps many people going because they have invested so much time into building a character and have trouble just walking away after all of the work. The designers take advantage of peoples competitive nature to want their character to be the best. After a year or so you max out the character and did all of the quests, and start to get bored, but then they come out with new worlds in the expansions with new abilities and it refreshes the staleness. You also build friendships through the game with people you regularly play with, so you feel that you are betraying them if you quit, especially as a leader who is relied on. They are designed to be all consuming.
I was going through some medical problems with my neck and the only chair I could stand to sit in was my high back computer chair, plus I could only sleep on a pillow for a few hours at a time. So, that game was a perfect fit. But as I healed I found I was still hooked. It doesn't help that I was single. A friend got it for me. The guy who got it for me was 55. He played with his 65 year old buddy. There were all ages in DAoC. I don't play any games now. The interest is totally gone. I am glad for it. They were the only two that I played on line.
WoT was just a First person shooter and it doesn't draw you in or require a time investment. That game was just pure straight up wild and crazy fun. TV seemed so boring in comparison. I would play each night for about 2-3 hours. But it was easy to walk away. Especially once the server numbers went down.