Preparation keeps pressure from becoming your first teacher.

There are two ways to learn most lessons: deliberately, in advance, or under pressure while something is at stake. Pressure teaches efficiently but charges a high price, and the tuition is usually paid in outcomes you cared about. Preparation is choosing the cheaper teacher first.

Think of a situation where you are currently planning to figure it out as you go. Ask what the pressured version would cost if it went badly, then spend a fraction of that cost now on learning it calmly. You do not have to prepare for everything, only for the things whose failure you would not want to pay for.