If you try and mine with a cpu it should point and laugh or say "youre doing it wrong".
WAAAAAY back in May of last year I did a little CPU mining. Then stopped when I realized I was spending more on electricity than the bitcoins I generated were worth. Bitcoins were selling for under a penny a piece, and I figured it cost a couple cents in electricity to mine them.
So if you think there's a chance bitcoin prices will be 10 or 100 times higher in the next year or three, maybe CPU mining now isn't crazy.
Just saying.