tripping on white squares

I have combinatorics and analysis at 9:30 and 10:30 on the same floor of a building Monday, Wednesday, and Friday. So I usually stop in the bathroom between classes. The wall around the urinal is covered with small, white, square tiles. While there, I make a game of trying to Magic-Eye the tiles: that is, refocusing my eyes to make the repetitive tiles appear to coincide differently. When done correctly, the result tricks my brain into believing the tiles are much larger and closer than they are. Whether done correctly or not, I also imagine that it appears to anyone else in the bathroom at 10:30 AM that I'm totally high.