Ask HN: Do you recall any book or course that made a topic finally click?

I remember reading 'The C programming language'

Also Code Complete - after reading I finally understood what good code should look like.

this book opened my eyes to how everything actually works... mostly :)

The Three-Body Problem, while a fictional sci-fi trilogy

reading Feynman Lectures of Physics (especially part-2 on Electrodynamics), made the real difference

Gaussian Processes - with Pattern Recognition and Machine Learning by Christopher M. Bishop

Haidt - Righteous Mind

Cosmos by Carl Sagan

William Zinsser's "On Writing Well"

King's C Programming: A Modern Approach much more enlightening

I would recommend Head-First Design Patterns as another great book for being able to “get” object-oriented architecture.

Tanenbaum's OS book