47. Don’t Cough on Me
Ah, not only a bad habit and a gross habit, but also one that can potentially spread whatever is causing you to cough to the other people around you. It’s pretty common knowledge you shoulder cough into your arm for everyone’s sake. Could work for your hand too, though then you might have to wash it off to get the germs off.

provided by constative.com
But despite it being common knowledge, as they say, common sense is not so common, and too many people did not get the memo to be more considerate of people around them when they’re hacking up a storm.