My son, last night at bedtime, asked me if there was a such thing as an infinity dollar bill. I asked him what he meant.

“It looks like one dollar, and it is one dollar, but it keeps on being more. And then you’ll have all the money in the universe in your very own pocket.”

I told him, no, there wasn’t a such thing as an infinity dollar bill, though I rather like the thought of it – sort of a conceptual vertigo, like all of heaven dancing on the head of a pin, or an entire universe in the nucleus of a cell, or consciousness and art springing from the gooey carbon muck of our brains, and so forth.”It sounds like a pretty cool idea,” I told him.

He crawled under his covers. “When I grow up,” he said, “I’m going to invent an infinity dollar bill.”

“I’m not sure they’ll let you do that,” I said.

“Oh,” he explained. “No one will know. It will be electric.”

“Will you need to plug it in?”

“No, it will have solar powered chips in it. And when I invent it, it will only be one dollar. But when I give the dollar to someone else, it will become one hundred dollars. And when they give it to someone else it will turn into a thousand dollars. And when they give it to someone after that, it will turn into ten thousand dollars.”

His eyes were shining.

“So,” I asked for clarification, “if you keep it, nothing changes, right?”

“Right,” he said “I can’t wait to invent this thing.”

“But what if you spend it?”

“Nope,” he said. “The infinity dollar only works when you’re giving it to someone. It can only be a present.”

“Why?”

“Because I’m inventing it,” he said. “And presents are awesome.”