The first hour after the idea hits

You know that feeling. An idea lands and your whole body wants to start. You open the editor, you sketch the schema, you start typing. By the end of the night you have a working thing and you feel unstoppable.

Three weeks later that thing is a mess you cannot untangle, and you cannot remember why you were in such a hurry.

I have started treating the first hour differently. I do not build. I write down what the thing is, who it is for, what it does not do, and what would make me abandon it. It feels like wasting the best hour I will ever have on the idea. But every project where I skipped it, I ended up spending that hour again later, at a much higher price.

The energy of a new idea is a resource and it is not renewable. The question is whether you spend it on building or on deciding what to build.

What do you do in that first hour? And has rushing it ever cost you more than the hour you saved?