Here's a big one for me: Whether or not someone shows a rudimentary understanding of how their own brains can mislead them.

It's easy enough to see it working in teenagers. They're the ones who realize that their emotions are going to be completely out of whack, their judgment may not in fact be 10x better than every adult around them, and proceed to compensate for it where they can.

It's not the same as knowing when to shout "Anchoring!" or "Sunk Cost Fallacy!". That's just knowing the password. It's a matter of being aware that your brain can think and feel things without consulting you, and not all of the things it thinks for you are good or right.