> If you read through the Big Red Book

This is a thoughtful response, but I can't help but chuckle at a response that starts with, just read this book!.

For me, well-written books are an enjoyable way to learn, and I'll admit I'm partial to that!

But of course you can learn in whatever way you like. Books are just a convenient example to point to as an indicator of how implementers, enthusiasts, and educators working with these techniques make sense of them and compare them to mutating variables. They're easy to refer to because they're notable public artifacts.

Fwiw, there's also an audiobook of the Red Book. To really follow the important parts, you'll want to be reading and writing and running code, but you can definitely get a sense of the more basic philosophical orientation just listening along while doing chores or whatever. :)