Five. One to screw it in and four to tell him how bitchin' he looked doing it.
or
Silly, WASPs don't screw in a light bulb, they screw in a hot tub.
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Two. One to assure the everything possible is being done while the other screws the bulb into the water faucet.
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The leaning tower of Pizza.
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The cow that jumped over the moon
or