3 kisses on the cheek, left-right-left.

NL

America: A big loud AHHHHH! when you fart. That way even people who didn't hear it or can't smell it can applaud your efforts. (Especially good when a gorgeous woman does it.)

#20 because India is disgustingly filthy and most of them are covered in actual sh#t

#8 Is that why they emigrated?

Unspoken customs in mostly unknown countries.

#9 no arguments from me

#17 UNLESS they specifically invite you to do so...then it is rude NOT to.

#23 Not exactly. The left lane is for passing. Otherwise, move to the right.

#6 A subtle difference... If you're in a country that drives on the left side (UK, Japan, etc.) people tend to walk on the same side that they drive - so the rules are reversed.