That reminds me of my Dad. Left school at the earliest opportunity, no qualifications to speak of, but had an intuitive understanding of how any kind of machine worked that has always been beyond me.
(He was also someone who rarely ever read a book his whole life, but one of the only books he did read was A Brief History Of Time. He is always a reminder to me that how society judges intelligence is completely messed up, and dismisses so many brilliant minds who aren't academic.)