If I have to hear someone playing music on their headphones loud enough for me to hear it anyway it drives me right up the wall.
I also go crazy at having to see people's involuntary foot vibrations even though I do it.
I don't think this sort of thing used to drive me quite this insane. Then again, I seem to be noticing it happening more often recently. I think I need to spend a week this summer where I don't leave the house at all except to post the strip.