Scroll through any newsfeed right now, and you’ll see news of a cruise ship with a cluster of fatal hantavirus cases—and a collective freak-out unfolding in real time. The situation is triggering an eerie sense of déjà vu and fear. In Reddit forums and on social media, people are telling each other in earnest that they can’t do this again, that they’re not equipped to retreat into their homes for months or get reacquainted with the art of social distancing. It’s too soon to know exactly how the outbreak will play out (though health experts insist that hantavirus is not COVID , and the risk to the general public is low). Hantavirus is rare and does not spread easily among people, and it typically affects fewer than 100 people in the U.S. per year. Yet the fear surrounding it is real and widespread, and—according to historians and psychologists—it makes a lot of sense. Here’s why your brain is doing this, and what actually helps when it does. The end of “global amnesia” Dr.…