Wait a second, I've never questioned it until now...but how have you avoid rain your entire life? I mean, It's gotta rain their in Oz, otherwise there could be no Emerald City...and your meterologists can't be much better than those clowns who predict the weather now.
So you're telling me you've never once been caught in a late Summer rain burst? Or taken a shower for that matter? Or dribbled a little water down your face when drinking water (by the way, i assume your insides are waterproof).