My wife gave me a sudoku puzzle book (editted by Will Shortz, one of the easy to hard volumes).  I knew about the game, but I never tried to solve a puzzle nor bothered to learn the rules.  Good thing I wasn't aware of this game during high school, otherwise I would have been in serious trouble ;). Anyways, to put things lightly, a lot of my free time has been spent solving sudoku puzzles. 

I find the puzzles fun to solve on two levels.  First, I like the pure logic of it.  It is fun to deduce directly or indirectly what a certain square's value should be.  Second, I enjoy that you have to keep multiple possibilities in your head at the same time. I find the process very close to debugging ;); I have to keep track of multiple threads in my head and identify what data they are operating on, just like the multiple possibilities for each square.  It never occurred to me that a puzzle that mimic that thought process.

Hopefully I don't lose too much sleep over it ;).  Have a happy new year and thanks for reading.  More content tomorrow....