I'm obsessive about keeping my drivetrain clean but you should know when your stuff is getting gunky. Just please remember that if you're ever just giving your chain a quick wipe down while installed, keep your digits away from the cog/chainring and go s-l-o-w. I lost a chunk of my thumb last year (that somehow managed to grow back!) and I've seen quite a few horrible pics on Sheldon's site of mangled/missing fingers.