Paul Graham, who co-founded the startup programme Y Combinator and has spent twenty years writing essays on clear thinking, set this down in a 2022 essay on putting ideas into words. It reads like a writer's complaint. It is a test you can fail in private.

In your head, an idea feels finished. You can see its outline, you nod at it in the shower, you explain it in a meeting with your hands. Nothing in your head asks for the next sentence.

A page does.

Try to write down why you picked your current price, and you stall at the second paragraph. You know the number. You do not know the reason.

The reason was a competitor's website you glanced at in March, and it has been passing for a strategy ever since.

The same thing happens with the hire you keep delaying, the market you say you will enter next year, the pitch you have given forty times out loud. Spoken, each one holds. Written, each one shows the step you skipped.

Talk lets you wave past the gap. A paragraph makes you walk across it.

Most people take the blank spot as proof they cannot write. Graham's point runs the other way. The writing worked — it found the hole before a customer, an investor or a bank did.

So today: pick the one decision you are most sure of. Give it one page and fifteen minutes before you open your messages, and write down the reason, not the decision. Where you stall is the part you still have to think through.

The page is the cheapest place to find out you were wrong.