He wanted to make a clean getaway!
or
Because he wanted to be on time.
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Two — one to change the bulb, and one to write a song about how good the old light bulb was.
or
Nothing, peanuts don't talk.
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Billllyuns and billllyuns. Light bulbs are part of the interstellar "goo" that pervades our universe; they are star stuff.
or