ON THE LAST day of March, in what felt like the longest month in human history, U.S. President Donald Trump stood at the podium at the White House press briefing and mused on the lessons of this pandemic illness. When the threat of this new coronavirus fades, he said, our habits will have changed. We may still be washing our hands more effectively than we did before, keeping distance from each other, not shaking hands as much. “Some of what we’re learning now will live on into the future,” Trump promised. “ I really believe that.”

But if past is prologue, then we are really bad at using the past as prologue. Five years ago, in the aftermath of a massive Ebola outbreak, epidemiologist Michael Baker bemoaned the vital lessons that we’d clearly failed to learn from prior outbreaks of disease. In recent weeks, many others have been taking note of how plagues of swine flu and the like have somehow failed to yield more funding for pandemic preparedness. They’ve argued that government officials flouted lessons from hypothetical pandemic exercises. Some have drawn parallels between our foot-dragging and denial of the Covid-19 crisis and the long delay in responding to the AIDS pandemic. As Howard Markel, a physician and historian of science, wrote in WIRED last month, “I feel like quoting Yogi Berra: It’s ‘déjà vu all over again,’ albeit a nightmarish blend of several déjàs vu into one.”

There’s a term for what’s been missing: “clioepidemiology.” Named after Clio, the muse of history, it describes the practice of studying information from past epidemics for advice about the present. Why are we so bad at doing this in practice? Isn’t everyone who’s ever lived through an ugly epidemic an armchair clioepidemiologist, almost by default? Why haven’t there been more of them spouting off about the lessons that they’ve learned? Or maybe more to the point, why hasn't anyone been listening?

It may be that this impulse has been canceled by a greater drive, to leave the terrors of the past behind. Indeed, some historians suggest that doctors who served on the front lines of fighting Spanish flu were reluctant to talk about it in the years that followed. Quarantines and bans on public gatherings during that period may have further shrouded the extent of suffering, while traumatized survivors kept their stories to themselves. It seems likely that a similar reticence to share followed other, past pandemics, too, as it may again when this coronavirus plague is over.