I am not saying that test pilots are not brave. They certainly are. However, they are brave + skilled + practice + smart + can perform under stress.
This is a slightly stretched analogy, but test pilots make me think of Alex Hannold. In the movie Free Solo he is presented as some insane person... it turns out that he is extremely intelligent + skilled + practices a lot + can perform under stress.
In both cases, they are the best of us. However, being brave/nuts is the elementary school version of understanding what it takes to be these people.