My university course in linear algebra taught me how to manipulate matrices. It was super uninteresting, and easy. I aced every test, but got a B in the course, because the professor assigned an asinine amount of homework (that I either aced or didn't do), perhaps holding the article author's view that:

> solving problems is the only way to understand mathematics. There's no way around it.

...without also understanding that doing problems is not a substitute for understanding.

(I'm still salty about that course. I've been doing linear algebra based puzzles nearly every day of my life and this professor somehow made the topic a boring chore.)

I complained about this to a friend who had also taken the course and he turned me on to Axler. I read through the first chapter, nodding along as I went. I got to the problem questions and couldn't believe what Axler was asking was even related to the material I had read through. I really struggled at first to understand. Axler was heavily juxtaposed to my previous experience. However, when I did understand, I didn't just understand, I grokked.

It was just such an awesome experience, and I credit that book in particular with breaking me out of a mathematics plateau and with liberating my mathematics education from a strict reliance on academia. The text is almost magical.