[tyrmored]

Hmm, yes. :set hidden is recommended so often in pretty much every introductory tutorial that in places I've assumed people who have basic familiarity with Vim are already using it.

In retrospect this probably wasn't wise of me; I don't use it myself, and I still run into the occasional Vim guru online who doesn't either.

I've edited the post with a clarifying note and given you a footnote. Thanks.