I don't need a lightbulb when I have the furnace ready.
To get to the other side.
None, the room is already lit.
Three - one to change it, one to not-change it and one to both change-and not-change it.
Because they immediately see something about you they can change.
Wife: What What child Husband: So you are not pregnant
Because Joy was stuck on the roof.
An AE I.O.U. P.S. Im proud of this one
Because he needed a poo.