Self-reference is cornerstone in Hofstadter’s Godel-Escher-Bach, a must read book for anyone interested in logic (and we shall rely logic in these days to stay sane.)

Here’s a bunch of examples of self-reference that I found interesting, curated just for you!

Barber’s paradox:

The barber is the “one who shaves all those, and those only, who do not shave themselves.” The question is, does the barber shave himself?

Self-referential figure (via xkcd):

Tupper’s formula that prints itself on a screen (via Brett Richardson)

A strange loop:

Venturing into coastal fractals:

Slightly off topic:I’ll add more as I go!