Yep, this has been discussed many, many times.
Like many others, I love the game. I played for many yrs. Then, I had two boys and coached for many yrs. I started "officiating" at their practices and then lending a hand during Rec League games in a pinch. I then started working Rec games in earnest and a patched official said I had some potential and should move to the next level.....and I'm still working at it.
Like others, it keeps me close to the game, out in the community, gives me exercise, the ability to help younger officials, and some pocket change.
Mostly though it's because I look good in black and white vertical stripes (insert photo here) and I love the ref groupies!