I find an interesting-tho-trivial bit of culture shock in going between North America and elsewhere (generally, in my experience): floor designations in buildings.
In North America the "first floor" of a building is usually considered to be where the lobby and ground exit is located.
Elsewhere, it's usually referred to as the "main floor", and the floor above that is the first floor. Indeed, in elevators of such buildings the "main floor" is often indicated with a zero button (and the basement is "-1" rather than "B").
Maybe there's an anthropology lesson somewhere on how and why these ideas diverged.
Evan Leibovitch, Toronto Canada
@evanleibovitch / @el56