Questions are places in your mind where answers fit. If you haven’t asked the question, the answer has nowhere to go. It hits your mind and bounces right off. You have to ask the question – you have to want to know – in order to open up the space for the answer to fit.
— Clay Christiansen
If you are not used to it, jotting down your ideas might seem superfluous. But it's a powerful way to expand your thinking.
The simple act of creating a tiny note with whatever is in your mind 'puts everything on the table' so that you can see and reason about it in a more tangible way – they become physical objects. This is becomes a space to explore possibilities without cost or commitment and an ideal context to run your creativity faucet; minimizing risk makes it antifragile.
Writing it down takes it off your mind if you know you will encounter it again at the appropriate time.