The End of the Beginning

The two adventurers were going along. Avon was singing.
"Stop!" cried Edward. "We've reached the end of the branch." With great care the two creatures edged to the very tip.
"The end of the branch," said Avon.
"The beginning of the sky," said Edward.
"Which is it?" asked Avon. "The beginning or the end?"
"It depends on what there's more of, the tree or the sky. Think of all the things that get in your way along the branch—leaves, bark, other creatures, a million things to slow you down. Now look at the sky."
Avon looked. "There's nothing there."
"Exactly. Which means that it will take longer to climb the branch. And if it takes longer, the branch must be bigger. And if the branch is bigger than the sky, that means we're at sky's end, but only at the beginning of the branch."
"You mean," asked Avon, quite amazed, "that after all this time, we're just beginning? I had no idea how far you have to go before you can start. Almost makes me want to stop."
"You can't do that, either," said Edward severely.
"Why?"
"Can't very well stop if you haven't started, can you?"
"Edward," cried Avon, "I never knew how important it was to start before you begin."
And turning around, they began.