As a new parent, you are expected to instinctively be an expert on taking care of a baby — from washing her hair to cutting her toenails. If you had your baby in a hospital, you might come away thinking the most important thing to know is how to give your baby a bath, but the numbers tell a different story. The bath-to-diaper-changing ratio suggests that you'll need to know a lot more about the care of a baby's body than how to bathe her.