I forgot to say I am a Master player of Tetris. According to Wikipedia, some studies reveal that playing Tetris boosts cognitive functions such as "critical thinking, reasoning, language and processing" and increases cerebral cortex thickness. In the article it is also stated that playing Tetris after attending/suffering traumatic events would reduce the risks of flashbacks and posttraumatic stress disorders. In any case, the only consequence I am seeing of this sudden addiction to Tetris is the Tetris effect, it is, picturing tetris combinations even when I'm not playing.
Positive effect: I could profit this just acquired skill to get my room tidied, yet I already know I won't, as I know I won't go to bed before midnight -that's how it works-.
Negative effect: I waste my time, as usual. Now, seriously, I should start getting concentrated instead of putting it off and, especially, stop being so absent-minded. It's already November and everything is around the corner.