We humans have an innate tendency to recognize patterns. This ability has helped us survive by learning important skills such as how to distinguish danger (predators and poisonous plants, for instance) from important resources (food sources and safe shelter) and knowing the right time of year to plant crops.
But the same ability can sometimes convince us we’re seeing a meaningful pattern when it isn’t there. Gamblers detect “patterns” in lottery numbers and roulette wheels, fortune tellers detect “meaning” in chance events and weave a story. As a society we carry all kinds of similar superstitions, such as “bad things happen in threes.”