When you discover a tiny papercut on your thumb by grabbing a handful of corn chips from a bag.
ouch!
I always discover it during the summer by getting a papercut full of old bay
Oooh that's even worse!
Today we were talking about food related pain... and old bay in the paper cut was actually beaten out by rubbing your eyes after playing with peppers. (and by we I mean my friends at lunch)
Jan did that once and still talks about it. I got her beat though, when I had to be pepper sprayed for training in the academy I shut my eyes at that time, but forgot about being careful later when I was showering (which reactivates whatever is left in your hair and on your skin). It got in my eyes and nose and I had another whole coughing fit. And for extra special fun, pepper-spray-water runs down your whole body...
I'm glad I only had to do that once (not counting the times on the street but those were more tangential hits, not full in the face like the qualifier).