None. They will never find a bulb that burns as brightly as the old one.
or
Executive Producers don't screw in a light bulb, they screw in a hot tub.
or
Someone stepped on its mouse.
or
Because he has such yuuuuge fans!
or
Only one, but she/he'll have to go out and buy the light bulb adaptor card first, which is extra.
or
I find you very attractive.
or