Comonads tend to well represent a notion of computing where you're isolating a particular section of your data in relation to its context. Compare this to monads which are often thought to layer computational context atop pure values.
This was the piece missing for me to understand comonads, worded exactly the way I needed. Thank you.
The author mentioned zippers, but for some reason I didn't quite get it (`a collection with one of the items being at the focus,` perhaps it sounded too specific for me at first)
Duality is your best friend when trying to understand nice concepts like monads and comonads. You automatically get two chances to examine every topic.