John is a bedwetter. For most kids starting school, this is no big deal but John still wore nappies to school.  But by age 12, wetting the bed IS a big deal as is still wearing nappies to bed. But by the time John left school he was still wetting the bed and while not allowed to wear nappies any more, still took opportunities to do so whenever he could. And the reason is simple... and complex. John is still a baby. A baby girl. And so nappies make perfect sense and using a toilet... does not.