Call it bravery, or confidence, but it is absolutely essential to making progress in anything. You can see its antithesis in bad code. Bad programmers leave old code commented out instead of deleting it, lacking confidence that they understand the task well enough to know that their new code performs sufficiently. Bad programmers copy pasta instead of abstracting and reusing, lacking the bravery to change code that works and potentially breaking it, lacking confidence to know that they can fix it.

I tell all my intern intends to "code forth bravely".