Journalists in search of trend stories are always waiting for that third shoe to drop -- because then you've found a three-footed man and, hey, that's a story!
The notion that the third time something happens marks a trend may well trace to "the rule of three," a longstanding quirk of Western culture. Examples of groupings of three abound (from the Holy Trinity to the Three Little Pigs to the Three Stooges) and the "rule" explains why story structures, slogans, titles, jokes, and just about any list seem to naturally "work" when divided into three parts.
In any event, our anticipation of events occurring in triplicate causes our attention to pique whenever a pair of similar events take place in a short period of time. So, after viewing the above video of a maniacal bird dive-bombing Financial District pedestrians and reading about the horse that ran wild along the Embarcadero, one must wonder: When will a third frantic creature terrorize San Francisco?
Similarly, within week's time of one another, both the "Gilligan Robber" and "Bad Wig Bandit" were sentenced locally. Is San Francisco due to be preyed upon by yet another hilariously named brigand?
Worse yet, will this as-yet unnamed hilariously named brigand and out-of-control beast join forces?
That would be the rule of three squared.