...and every work day, for 30 years, he has taken the elevator down to the first floor, has gone to work, and at the end of his work day he has come home by taking the elevator up to the 26th floor and from there walks the rest of the way up by means of the stairway, to his home on the 45th floor. There is nothing unusual about the building or the elevator, which is in working order.
Why does he walk up those stairs instead of just taking the elevator home?