I once worked with a guy who was an incredibly good developer and I was surprised when he didn't see anything special about the number 64 (i.e. a power of two) - turns out that he'd never done any bit fiddling type work so he hadn't had to think in those terms. It wouldn't surprise me if a lot of people hadn't heard of "mod" either....
A huge majority of programming work is basically just CRUD stuff and other data shuffling. It’s not surprising that someone wouldn’t have needed to work with big shifting (or modulus) in that case.
He was an expert in complex multi-organisation enterprise integration and was the go to guy to work out why horrific distributed transactions were failing... He also did a lot of cool stuff as side projects in his own time - just none of them happened to involve worrying about powers of 2.
