Just offering another point of data, your observation of the "same space with no overlap" and the anecdote about the restaurant hits so true for me! Almost the exactly same thing happened to me, Spanish nearly the whole time. Later, with a coworker, 100% gringo experience. Hilarious! The alternation between places like this as you walk up 24th always struck me as notable.

This couldn't have been later than 2011, at which time the zeitgeist was replete with jabs at the ongoing gentrification. :)