This always surprises me as I'm younger millennial and my Gen X dad always feels more technologically behind than me.

But it's funny because I'm only so into computers because of him as he had things like Windows 3.1 and 95 and 98 in our home from a young age and he even went to school for C++ but he doesn't really remember it (it got him an accounting gig) and his pursual of technology these days is pretty limited to pre-built stuff from Samsung and Sony than any real grasp of how it works. I struggle to get him to show even passing interest in something like Linux (like, I get liking Windows; you grew up with it: you're more comfortable with it. But not even curiosity, even if you'll never use it?).

Expert on Excel and OneNote (because it's his daily bread-and-butter) but probably would ask for my help on rotating a PDF.

What OP describes sounds much more aligned to my millennial peers than the bulk of Gen. X I know.