This is indeed a great topic! I loved it from the moment I went at the meek age of 2! But when did I start to be obsessed with it? Hmm...
It stems from my uncle, who lives in Florida with the rest of my mother's family. Without divulging too much information, one of my uncles has a very hard life taking care of his quadriplegic older brother. His favorite place to escape has always been WDW and he has used it as an escape. I always wondered why he was so obsessed with it and just what was so cool about Walt Disney etc...until I went there with him on one of my trips, probably 1999, and that's when I really started to see WDW through his view and not just as the child that I was. From WDW's rich history, to Walt's legacy...I just started to fall in love with all of it. My family had just gotten the internet as well, and I remember my mom having to PRY me away from the PC at night, as I would be looking up as much as I could about WDW online.
I drifted away for a bit when I got turned into a bratty teenager, but when I graduated high school, I saved up my money all year with my best bud, and we took a trip to WDW (his first!) while all of our friends were getting busted for underage drinking at the Delaware beaches during senior week. HA! Probably from that trip forward (2005), I became a WDW-holic.
When I learned about things like forced perspective, the windows on main street, area music loops...I felt like a kid in a candy shop! I still love to learn all about that stuff and all the hidden history and culture that's in WDW. Whether it was something nerdy like "what key signature is MSEP's music in?" or something technical like "How do they do the ghost scene in Tower of Terror?", I suppose curiosity combined with a LARGE affinity for fun have primarily driven my casual interest in WDW to a full-blown passion.
As much of a critic I am about the place, I really can't get enough of it. (I suppose that's WHY I'm so harsh sometimes...because I want it to be the very best it can be, 'cause I love it so darn much!)