Coming from CVS and ClearCase it took me some time to adopt to Git. The fact that it was distributed was confusing at first, for example, because I thought that would cause chaos. But the way we used it was actually not “that distributed”. But once I understood how it worked, not doing DVCS was “the wrong way” immediately.
As an ancient ops person, I was unfamiliar with version control before git. So git has really changed how I look at look at version control!