When I re-read "Left and Right: A Non-Euclidian Perspective," I was struck by RAW's comment that that Nietzsche made a "powerful impression" on him and that "I still re-read one or two of his books every year, and get new semantic insights from them."
As I have never read Nietzsche, this raises the question of where to begin.
I pulled out my trusty copy of Eric Wagner's An Insider's Guide to Robert Anton Wilson by Eric Wagner, and sure enough, Eric is on the case, noting that Wilson mentioned Nietzsche in both of his lists of books that everyone needs to read.
One list includes Nietzsche's Twilight of the Idols and The Anti-Christ. The other lists The Anti-Christ in H.L. Mencken's translation.
When I looked in the Kindle store on Amazon, I found the Mencken translation of Anti-Christ for 99 cents, so I bought it. There were cheap editions of Twilight, too, but I couldn't figure out which translations were good.
I once saw a Gahan Wilson cartoon that showed a man sitting at a bar, with a robot standing next to him. The man with the robot tells another person in the tavern, "He's programmed to take me home when I begin quoting Nietzsche."