[bbeonx]

The dude/dudette figured it out on their own which is what math is actually about. Who cares if it's well known? Knowing a fact because you learned it in a class is cool and all but it's not the only way to acquire knowledge, and I would argue not even the best way---just the most efficient fact/hour ratio.

[giomasce]

You are right. Sometimes the most sticking facts in my head are those that I rediscovered by myself, because that helped me to see their actual importance, which might have not been that apparent while hearing about them in classes. There are teaching theories in which the student is not supposed to learn about something, but they are guided to rediscover it by their tutors.