Hot, because you can catch cold.
or
The strange charm of a top down bottoms up.
or
Three:
One to write the light bulb removal program,
one to write the light bulb insertion program, and
one to act as a light bulb administrator to make sure nobody else tries to change the light bulb at the same time.
or
Bike helmets don't fit hippos
or
Because there are too many ears.
or
I've got you covered!
or