btw, if you didn't find an in-joke [1] funny [2][3][4][5] then it's probably because of a very good reason :)

Knuth himself found it funny [6]

[1] https://en.wikipedia.org/wiki/In-joke

[2] https://groups.google.com/forum/#!topic/alt.folklore.compute...

[3] https://www.reddit.com/r/ProgrammerHumor/comments/38gt65/was...

[4] http://texthook.com/blog/2013/07/01/reading-knuth/

[5] http://tal.forum2.org/story_45

[6] http://www.tug.org/TUGboat/Articles/tb17-1/tb50knut.pdf (page 10)