Of all the things that bother me, I think the most annoying thing is when you're sitting in a confined, but public, space and all of a sudden you hear "snap....snap...snap". Someone is cutting their fingernails. Yuck! The noise bothers me when I'm in the privacy of my own bathroom trimming my own nails, but why would someone trim their nails in public?
Its almost up there with carrying on complete conversations while you're in a public bathroom.
What are your pet peeves?