I always felt like quaternions weren't a perfect fit for 3d rotation, and when I finally learned about bivectors my faith in the elegance of mathematics was restored :D
I liked this article: https://marctenbosch.com/quaternions/
Yikes! This is the sort of thing that scares people away from complex numbers from a young age.
> Personally, I have always found it important to actually understand the things I am using. I remember learning about Cross Products and Quaternions and being confused about why they worked this way, but nobody talked about it. Later on I learned about Geometric Algebra and suddenly I could see that the questions I had were legitimate, and everything became so much clearer.
Clearly, "who cares as long as" is not the true belief of the author, but rather a mocking call-out of teachers who do think that way.