When I was a grad student at the University of Wisconsin in 1978, I called Dennis Ritchie at Bell Labs to tell him about the work I was doing with the Unix line editor. I had added structure. You could nest lines under other lines. Dive and surface. Move a line up and everything under it would move up too.
I also built a parser into the editor so it would understand the structure of Pascal (for some reason I chose Pascal and not C, I don't remember the rationale). So you could import a bunch of code and it would automatically arrange it into a hierarchy that my editor could edit.
I got off the phone with a glow. For a student to connect with an adult that way, especially a hero like Dennis Ritchie, whose code we were studying, whose coding style was what I aspired to -- that was a thrill. Of course I still remember the feeling even if I don't remember all the details.
I read somewhere that, while he wasn't as famous as Steve Jobs, that his legacy was on the same level. I totally agree. He created the modern interactive operating system. He taught a generation of programmers, of which I am luckily one, how to think like a programmer. That loving code was exciting and rewarding. And he did this all by sharing with everyone the results of his own creativity, totally. Long before "open source" or "free software" were rallying cries.