Ever heard of the Tetris effect? It’s where you play so much Tetris that the game starts to seep into your thoughts, your dreams, your half-waking hallucinations, and pretty much every part of your reality that has nothing to do with Tetris. Well, I do a lot of crosswords—by “do” I mean both “solve” and “make”—and it turns out the “crossword effect” is also a very real thing.