this is a sort of follow on to my previous post and from that and this image you can tell why. - glass display cabinets. specifically it started with shower ones.
we didn't have one when growing up but just a bath and shower curtains (now thats another one). somehow i accidently discovered that if you leave soap on too long it would dry out and slowly make your face and of course skin tighten and harden. the sensation was .... and it worked on my hair too.
i must of been on a trip somewhere, possibly a vacation at a hotel somewhere with my own bathroom and shower and time to kill. glass display case shower and soap. standing perfectly still as it dried.