I know many of you seem to be invincible-never falling ill, always riding to work-but for those of you who aren't: How sick are you before you don't commute?

I drove today but with a hacking cough and head congestion I didn't want to feel like crap arriving at work. I probably could have powered through like I did yesterday but since I feel worse today anyway I figured it wasn't worth it.

How often are you out of commision for illness (non crash related)?