He probably was interested in it. Not everyone has a traditional background or even day job in the area they're passionate about. One of our neighbours growing up in a small village was a nice old retired man who barely had any formal education, years later I found out he was publishing original maths research online. There's also a guy from Finland who IIRC was a bus driver who is putting great C++ low level graphics and retro programming content on Youtube.

Lots of under-recognised talent is eveywhere.