I think this one is hilarious, because it is so true:
People who like to touch really like touching, and people who do not like to touch really dislike being touched. You will need to watch your colleagues for clues on what they are comfortable with.
… and I like this one for the alternate perspective it inherently embodies:
Do not be afraid of hurting someone’s feelings by responding “no” to an invitation. People will be offended if you say you will attend and then do not come.
Which ones struck you?