Climbers trust the rope because they checked the knot. Courage works better after you’ve done the prep.

Nerve is not the absence of caution but what caution makes possible. The climber is calm because the preparation is done and can be relied on, so attention is free for the part that requires it. Confidence built on checking holds up under load in a way that bravado does not.

Before the thing you are dreading, list what could actually fail and handle the items you can handle. Rehearse the opening, bring the spare, confirm the time. Then stop preparing, because preparation past a certain point turns back into avoidance.