Kakuro
I started into the kakuro puzzle while the single serve coffee maker percolated in the background. Mistake number one: a puzzle that complex should never be attempted until you are fully awake. I could fake a sudoko puzzle. Listing one to nine is not that hard, even at 6 am in the morning. But once you get into sums and cross sums and unique numbers like you do with kakuro, you need all of your brain cells up and fully operational. Otherwise you are trying to bail out the Titanic with a single thimble.
