None: they just deny that the bulb ever went out in the first place.
or
Separation anxiety.
or
Stable tennis
or
I just can't think of one atm.
or
Because she wanted to hit the high C's.
or
Bozo The Clown has real hair on his head.
or
Anywhere it wants to
or
A Broncosaurus or a Tyrannosaurus Tex.
or
Twenty. One to hold the bulb, two to turn the ladder, and 17 to be on the guest list.
or
Bar magnets have poor homogeneity.
or