It's surprising how sensitive people are to slight changes in their environment. Specifically, it's hard for us to adapt to them.
For example: I recently cleaned my room, and moved my desk chair from one corner of the room to the other. When I go to throw something out, however, I still instinctively go the original corner, where there is no longer a trash can.
A weirder example: We're in the process of removing carpet from our stairs. I was running down the staircase, and almost tripped when I reached the hardwood section; the drop to the next step was a half an inch larger because their was no carpet.
A half an inch difference can really mess with your stride. As unorganized as people can be, I suppose we're all detail oriented by instinct.