Because it would fall over if it lifted the other one.
or
Well, first let's talk about the concept behind this whole "light bulb" thing.
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1,000,001: One to change the bulb and 1,000,000 to rebuild civilization to the point where they need light bulbs again.
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Because he wanted to be on time.
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O I C U R M T
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Bozo The Clown has real hair on his head.
or