It's spitting!!!

Why do we feel the need to keep ourselves dry? We're mainly made up of water, so you'd think we'd feel fine about getting a little wet. I guess it varies from person to person, but the human race in general will cover up when the rain starts. Maybe it's a self preservation response to the possibility of reducing your body temperature. Maybe it's the fear that osmosis (the passage of water of varying volumes from one place to another through a membrane, i.e. in this case skin) will somehow either expand you or shrink you. Maybe we're all just so self conscious that we don't want to ruin our makeup/clothes/hair etc. Maybe it our way of defying evolution, of saying "No. I started in the water, I refuse to return".

Or maybe it's just the fact that we don't want to sit around all day in wet clothes.....but then that begs further questions, like, Do nudists cover up in the rain?