My wife recently asked me to put our younger (seven-year-old) son in the shower with me because he needed a bath and it would "kill two birds with one stone".  I was in a hurry to finish and started washing him up.  In the midst of doing so, it dawned on me: "He can probably do this himself." I asked him if he could wash himself, to which he responded affirmatively.  I said I would just finish since I was trying to get done quickly, but I realized that I am so used to washing thirteen-year-old Anthony that it didn't immediately occur to me that his younger brother wouldn't require my help.