Back in the day when I was a full-time stay-at-home dad, I sometimes had women compliment me on knowing how to change a nappy (diaper) as if it was some kind of miracle, or, in a situation where I could offer assistance, they'd say something like, "You're a man, what would you know about children?" The fact is, there are skills that aren't apparent just by looking, so assumptions based on most likely probability are perhaps almost inevitable.