Reverse Engineering
A permanent skill is the ability to reverse-engineer works and outcomes.
Steve Wozniak's best work came out of things he never did before. His skill was understanding the desired end result and getting it done. Steve wasn’t skilled in how to design a floppy disk printer interface, or how to get a computer to read certain types of data. When the time came for it to be done, he reasoned from First Principles—designing his own from scratch without knowing the “right” way others did it. Burrell Smith, an early member of the Macintosh team, was the same way.
He didn’t go to college but he was one of the best with circuits. His success was the result of reverse-engineering what others had done to be able to build new things on his own.
This skill is one of the most important skills in self-education. It's one of the main drivers of Specific Knowledge