> He said, “If you get the awk programming language manual…you’ll read it in about two hours and then you’re done. That’s it. You know all of awk.”

It's hyperlinked to the Gawk manual, but it seems likely he actually meant A, W & K's The Awk Programming Language (1988), which you could conceivably read in 2 hours, as it's a joy to read. I used it and The C Programming Language as exemplars of great documentation when writing my own.