You can study swimming all summer from the pool deck. You learn it the minute you get wet.

Preparation has a limit, and past it the only information left is in the doing. Watching and reading build a picture of the skill, but the picture is made of things other people noticed, and it cannot include what your own body does when the ground goes away. That part has to be collected first hand, and it starts the second you get in.

Work out how much more preparing is genuinely useful for the thing you have been circling, then set a date to begin. Preparation past that point is usually a comfortable way of not starting.