[Expecting this, Chaosbringer has an answer at the ready.]

Let's take a simple example. You're looking at a staircase. Falling down it will hurt, of course. So obviously falling down it is something you want to avoid, it'd be a mistake.

If you don't want to fall down it, you walk down carefully. If you're afraid to fall down it, you don't walk down at all. It's oversimplified, but the point's right there. You cross the line when you don't act, even when you need to get somewhere or do something.