I’ve known few exemplars like this one. But at least 2. One made a flight simulator for 737 in the backyard that was used regularly by airline pilots to train. The other made a complete discrete FM stereo transmitter, mounted his own radio later. He was 16, and it was the early 90. So all from books.

Both guys brutally failed in the first year in the University. They dis not like theory, they wanted to make.

So… i dunno. 2 reference points there.