Books that compelled you to go down a rabbit hole study of the topic?

Question

Have you ever come across a book that you didn't know would blow your mind out of proportions so much that you had to go down a rabbit hole of learning more about the book's subject and really benefitting out of it in the end?What was that book and what was the experience like?While going down the rabbit hole, what other books did you read that are worth the mention?

cmollis · Accepted Answer

Unix Network Programming - Stevens. (this is kind of a classic book on the subject.. but at the time, I had never heard of it).

leed25d · Answer

_On Lisp_