I seem to expect everybody I meet to be able to do all four of the following:

Swim
Ride a bike (by which I mean a two wheel bike with no training wheels)
Ski
skate (ice, not roller)

I don't expect people to be able to in-line skate or roller skate though...which is weird.

I asked a few friends and now I'm asking you. Incoming...thingie...poll. Yeah.