I recommend everyone should read some well optimised code occasionally, and figure out how it works, to see how it's done.

I didn't know much in the way of assembler techniques before reading the Elite code. For example I didn't even know how to do things like multiply or square root, or draw lines efficiently. That's where I learned those things.

It did take quite a lot of studying the printout to get it. So many "aha! that's how they do it" moments.