Skyscraper

There was this guy and he lived on the 52 level of a skyscraper, and
worked on the 3 floor. When he goes to work he uses the elevator, however;
when he come back up to his apartment he uses the elevator to the 36 floor
and then has to walk on the stairs for rest of the way unless there is
somebody else in the elevator.

Why does he need to walk the rest of the way, if there is nobody in the
elevator?

Because he’s a midget and he can’t reach the button for 52 floor.