I also have "my" spot in the bike rack, and I'm usually one of the first to arrive, so I almost always get it. I'm not too torn up if I don't, though.
The rack I use works best when bikes alternate sides of the rack in consecutive spots. What really grinds my gears is when some idiot skips a spot, so someone else has to park on the same side as another bike in an adjacent spot. It's akin to the jerk who parks his car over two spots in a parking lot.