Questions I Have

This morning I am doing the laundry and I find several pants and a lot of shirts of the twins', but only 2 pair of underwear (and WHY are they called 'pairs' of underwear anyway?, what's so 'pair-ish' about one article of clothing?) Why is that? Perhaps a short, friendly discussion (again) about personal hygiene and what to put on after a bath is in order for breakfast conversation.