Humpty Trumpty wants Mexico to pay for it all.
or
Three: One to screw it in, and two to talk about how much better it is than with a man.
or
Two. One to take out the bulb and drop it, and the other to try and sell it before it crashes (knowing that it's already burned out).
or
Only one, but the bulb has got to really WANT to change.
or
One is a blood-sucking parasite, the other is an insect.
or