Humans are insanely good at seeing patterns. We see patterns in things we're not even supposed to, and we do it all the time. It's why we can see animals in clouds and faces of dead celebrities in malformed potato chips.
It's not just visual patterns we’re good at. One really interesting example of this is the ‘red flag’ phenomenon, where you just get a bad feeling about someone, even if you haven’t actually seen them do anything that warrants caution. In many cases, this red flag turns out to be right all along. That’s the pattern recognition in our brains going off. There may have been just something about the person that set off your internal alarms. Perhaps maybe you’ve subconsciously noticed similar expressions, speech patterns, behaviors, etc. in people who did actually turn out to be bad in the past. Your brain keeps extensive records of that sort of thing whether you're aware of it or not.