Why writing it down matters more than thinking it

You might be thinking: "I already know what my product is. I don't need to write down what it isn't."

You'd be wrong, for an interesting reason.

Your brain in week one (now, reading this) and your brain in week six are different brains. Week-one brain is energized and clear. Week-one brain remembers exactly what was important about the original idea. Week-one brain is the brain that wrote the offer sentence in Lesson 2 and felt good about it.

Week-six brain is exhausted. Slightly bored with the original idea. Dazzled by every shiny new feature it scrolls past on Twitter at 11pm. Week-six brain will absolutely build things that week-one brain would have laughed at.

The exclusion list is week-one brain's letter to week-six brain. Written down because week-six brain does not trust week-one brain's memory and would override it without proof.

The list has to be on paper. Not in your head.

So what goes on it?