It does not mean that your application was singled out for especially fast processing. Merely that (like most applications) it was uncomplicatedstraightforward enough to be decided quickly once someone got around to looking at it, and someone did so quickly because you had the luck to apply on one of the days where they didn't have much of a backlog.
(Mathematical queueing theory predicts that every once in a while the backlog will drop down to nothing, unless you're so short-staffed that it will keep growing without bounds).