The most interesting part to me was this: "He’d been telling a version of that same story every single day for months and months during development—to us, to his friends, his family. He was constantly working on it, refining it. Every time he’d get a puzzled look or a request for clarification from his unwitting early audience, he’d sand it down, tweak it slightly, until it was perfectly polished."
I did the same thing for 12 years as CEO of Postmates and I still do it when I work on new ideas. I thought it was something I just did. But reading this I have to assume it is more common.