Being the father of girls is a kind of illness, in its own way - since any guy who has tried to live in a house with a wife and two daughters is, without any doubt, going to go certifiably nuts.
With girls, there's an insecurity that starts early on. It hangs around them, like some annoying kid from down the block who won't take the hint and go home when dinnertime comes. And moms are usually not great at giving their daughters confidence.