Only one, but the light bulb really has to want to change.
Make that change
None you know of. Since they signed a Non Disclosure Agreement to not talk about it.
None, because they keep on asking why all of the other light bulbs in the house aren't being changed at the same time.
None a burned out bulb can't catch a waiter's eye.
0, the light bulb has to want to change itself.
Squirrels they're the best at getting nuts out of their shells.