A Man Said to the Universe

When I saw the Calvin and Hobbes cartoon the other day, I recalled a poem I read several years ago. After some head scratching and scouring the bookshelves at home, I found it:

A Man Said to the Universe
— Stephen Crane (1871-1900)

A man said to the universe:
“Sir, I exist!”
“However,” replied the universe,
“The fact has not created in me
A sense of obligation.”