Stanford Professor Ron Howard used to ask students to assign every exam response with the probability they thought they were right.
If you got a question right and assigned a high probability to it, you’d be rewarded with more points. If you got a question wrong and you assigned a high probability to it, you’d be penalized by losing more points.
He cautioned his students to never assign a probability of 100% to any answer, because if that answer were ever wrong then they’d get a score of negative infinity which meant failing the course.
As long as the students never assigned 100% certainty to any of their responses, they stood a chance of thriving in the course.
The goal of this exercise was to offer a simple yet profound life lesson that would hopefully transcend the classroom: there is always going to be some uncertainty that cannot be resolved, so it’s in your best interest to not be 100% certain about anything.
As long as you are willing to maintain some uncertainty, you retain the humility required to be able to recognize when you’re wrong so that you can learn and improve in your domain.
The second you give into the desire to be completely certain, naivete becomes a rapidly expanding vulnerability.
In Howard’s class, it meant failing a course.
In life, it could be much more costly.