Performing on stage.
Playing in a football game with millions of people watching.
Speaking to a live audience.
Presenting to the board of directors.
Making a good impression on a first date.
Answering questions in an interview.
Driving a bike in traffic.
Cooking for guests.
Writing an exam.
Talking to a potential customer.

Is all about turning up on that day.

It can rarely be done without practice.

It is the same with ideas.

When the gun is to your head, you either figure it out or you die.
When in trouble, you need to come up with ideas to get out.
It can rarely be done without practice.

Here is a wonderful article by James Altucher on how to be an idea machine.