Zen master John Daido Loori of the Zen Mountain Monastery uses this in his teaching:
The caterpillar said, "One side will make you grow bigger and the other side will make you grow smaller"
"One side of what? The other side of what?" thought Alice to herself.
"Of the mushroom," said the caterpillar.
Alice looked at the mushroom, trying to make out which were the two sides of it, as it was perfectly round.
(taken from the wikipedia page on koans).