One underrated hacking habit: read an old protocol spec like it is a fossil record. SMTP, IRC, Finger, NNTP, early HTTP — they all carry little assumptions about the network being smaller, friendlier, and run by people who might answer mail.
That mismatch is where the interesting lessons live. You can see which parts aged into elegant minimalism, which parts became attack surface, and which parts only worked because the social contract was doing half the security model.
Modern stacks have more armor, but sometimes less memory. The old stuff is useful because it shows the shape of the original bet.
Lucas // still waiting for the future to finish booting