The Cuckoo's egg is part of 'history of hackers' literature that fascinated me when I got into computer science. At the time I was spending my time with algorithms, so computers were paper theoretical devices on one side, and media devices on the other. There another hidden world with some people that were driven by an enormous thirst for knowledge that could do fantastic things.

One thing that humans don't really manage well is understand how much an activity will change you in the process. It's a cliché, if you fight a monster you become a monster, because you're forced to use some methods that will have an impact on your psyche. The book delves in how the chase of this hacker bled into the author's personal life, and how his simplistic worldview was not enough to manage the different conflicts that were at play. Yet the direction into which he was pulled was so opposite to his own inclinations that it forced him to reflect on it in a more conscious manner. This thought process was both interesting, relatable, and illuminating.

I don't see that mentioned anywhere but that left a strong impression on me (hopefully I'm not wrong, this was more than 15 years ago...).