What helped and what didn't?
What advice would you give someone who wants to become a good hacker?
P.S: A good hacker is someone who when given a problem can break it down and solve it in a correct way. Now that problem may be purely mathematical or something related to computer science or something else. Basically a great problem solver.
I do not believe hackers think in this way being a correct way. A hacker will pride themselves in finding a thousand ways to accomplish something with emphasis on finding the smallest, simplest, most unorthodox ways that nobody would have thought of. A hacker will not be bound by doing things the correct way. These are people with an incredibly powerful and unlimited imagination.
An example would be that someone writes a massive program to break encryption on something, then a hacker comes along and reverse engineers the protocol and writes a 10 line python script to exploit a design flaw/bug and accomplish the same end goal in less time, using less memory and less CPU time.
Hackers are good at understanding the big picture and breaking things down into generalizations that can be attacked or can not be defended against. Another example would be corporations that make super expensive firewalls that are meant to prevent data exfiltration, then a hacker is told data exfil is not possible because of the $2 million dollar firewall. Challenge accepted. They will find a way around that can not be defended against. This is not a theoretical example. I observed a friend play this cat and mouse game with one of the biggest firewall vendors. In the end he could not be blocked. Shout-out to The Godfather
I will leave the software development examples to the proper software devs here.