S1·E22 A Life in the Day

Harry sees five patients: a week-old baby, a five-year-old whose father denies the boy's onset diabetes; a seven-year-old curious about sex; an eleven-year-old having the cast removed from his arm; a belligerent 14-year-old who uses drugs; and an 18-year-old picking up his medical records before going away to college. The end of the episode reveals that all of these have been the same patient at different ages.