Writing is usually treated as the step after thinking: you figure it out, then you write it down. The order is wrong. Writing is how you find out what you actually think.
A vague idea can survive indefinitely in your head. The moment you try to write it in plain sentences, the gaps become obvious.
Teams that write their decisions down make better ones.
The Cheap Forcing Function
A one-page memo exposes a weak argument faster than an hour of conversation.
If you cannot write it clearly, you do not yet understand it.