I love this, I really do. The Hemingway story is, as you say, apocryphal, but it's also a great example of how you can tell a story in just a few words. It also exemplifies Hemingway's writing style, which has been likened to an iceberg - only around one-eighth of an iceberg is above the water. That's what you see on the printed page.
Oh, I guess I should submit my own six-word sentence too, right?
"Taste this. Can you milk fish?"
I love the absurdity of it.