Thanks for posting this. I saw a video[0] with Milton Friedman in it that quoted this essay but didn't understand it's origin.

https://www.youtube.com/watch?v=67tHtpac5ws

Very interesting. I had never seen that, but had seen this other essay which is clearly based on it, which supposes the complications that might arise if the FAA required pencils to certified for aviation use. I think it's a lot funnier than I, Pencil.

http://www.rstengineering.com/rst/articles/tsodpencil.pdf

Whenever I think of "I, Pencil", for some reason, I think of John Wick.