I also joined a world top guild (bouncing around #2 in Europe around the time I played). It's a totally different experience from even that described in the OP,

I also joined a world top guild (bouncing around #2 in Europe around the time I played). It's a totally different experience from even that described in the OP, and other people's experiences getting sucked into life at the mid-level-40s. I have to say to those who found levelling addictive, hardcore raiding is going to be ten times worse. I'd agree in general that those who really focus to zerg a new boss as fast as possible end up playing less over time, but I also found many many people of my old guild who played almost constantly once content was cleared. Several would strive to have multiple highly geared alts, clearing the same content multiple times a week on alts as well as mains in case the next encounter needed a different class composition. Few of the people I raided with had jobs or openly talked about them. People who turned up once a week for the farm raid were mocked as being casual. It's addictive in the way a job is addictive. Once your mind accepts there is some reason for you to be in this raiding cycle, and especially if you play an integral role (I was a main tank and tank officer), you feel you have to be there every night - and it just becomes the centre of your world, despite not receiving any real world compensation. The acclaim, worldwide achievement and knowledge of being part of something that is undeniably awesome all tie into it.