He got me to teach him basic C syntax and then took off on his own, writing a game. After a few weeks of hacking, he presented me with a decent Asteroids clone, "I don't see the point of C."

The funny thing is, when I looked at his main.c file, the entire code was written inside the main function, with copious use of gotos. He had essentially tried to speak BASIC using C.

APL isn't an Algol-like, and you're probably going to have a bad time writing APL trying to use the cognitive tools and intuitions you have as a programmer of Algol-like or even functional languages. This includes the tendency to reach for libraries, when you can, for example, implement an entire U-Net CNN in 30 lines of APL and be competitive with PyTorch performance.

In my (budding) experience, to "get" APL you have to laser-focus on writing beautiful, concise code from the onset. It feels painful as a student to spend weeks writing and re-writing just to produce 2 lines of code, but in the end those 2 lines will be doing the work of 20 lines of Julia, or 200 lines of C, and feel like a pure, direct mathematical expression of the algorithm you intend.