Two — one to screw it most of the way in and the other to give it a surprise twist at the end.
or
Humpty Trumpty wants Mexico to pay for it all.
or
Microwaves.
or
I was amazed, I never knew they worked.
or
Two. One to change the bulb, and one to write a song about how good the old light bulb was.
or
[A Condesending con descending]
or