I got to be very good at Tetris. Maxed out the original Russian version on max possible score a couple of times. Then it got scary. I realized I was thinking about Tetris day and night, dreaming about it, etc. I had to quit, permanently.
Then a couple of years later, it got worse. A game out called Blockout: 3-D style Tetris with segmented pieces in various dimensions, from one to five cube-segments in length. I played that, got to be very good at it, too. But that was like crack for mathematicians. My poor brain went into overdrive, obsessing about spatial relationships, fitting hallucinatory 3-D segments together for days on end after an intense session. When I finally quit this game, it took a month before I stopped dreaming about fitting blocks together.
Word to the wise: if you are literally dreaming about it, take a break.
It's been ten years since I dreamed about any games I was playing. Cold turkey appears to work, but one is left to wonder if there might be a "point of no return" past which lies madness or painful withdrawals.