Most people have summed it up pretty well, but I'll add my two cents.
When I first started working at Disney, my excitement was as anyone's would be. I'd go to the parks all the time. Disney was my life 24/7: eat, breath, work, play... ALL DISNEY, ALL THE TIME.
Now, I have toned things down a bit. Disney is still my life, but it is also a job. I don't always spend my days off at the parks anymore. Dumb tourists bug me a lot and there are so many things I could point out as wrong that I normally wouldn't see. You get to see where budgets are cut, how cast members really feel, how neglected some things can get, and that there is always a different side to the magic... an ugly truth or a hidden technicality or a shocking realization. You see what works and what doesn't, what gets fixed and what doesn't, who works hard and who doesn't. You see the best and the worst, and yes the "pixie dust" sometimes just becomes "glitter".
But I haven't lost the magic. There are far too many things on property to experience, far too many details to be amazed by. Despite seeing backstage Mickey yesterday, onstage Mickey will always be real, my pal, and the best "boss" I could ever have. The emotional take away that rubs off from others is what sticks. I get reminded everyday about the magic I make in my job whether its a "kid's say the darnedest things" moment or the sincere thank you I get from adults. I get to play and pretend while doing a job and getting paid.
Working at Disney is not for everyone. It does take a very VERY, and I MEAN VERY VERY patient person, but if you can laugh at the bad times and buy into your imagination, you'll never lose the magic. It's special to be a part of and something to take pride in.