I think he's right in general about capturing the detail. You must be able to write down succinctly what you're selling before you talk about it to an audience.

I think he's right in general about capturing the detail. You must be able to write down succinctly what you're selling before you talk about it to an audience. It's analogous to writing down your design for software before you actually code it. If you can't then something doesn't add up. If you want to produce a bullet point powerpoint from the document then it should be possible to do it in a few hours. But the reverse isn't true.