During the nearly four-year siege, people’s sense of community, memory and even time all transformed, he said. Now, Mr. Bozovic and other survivors are already sensing echoes of that time in the slow-rolling pandemic, which is anticipated to last, barring a miracle, perhaps one to two years.

Research on the effects of epidemics and sieges, along with the emerging body of knowledge about the coronavirus, hint at what the coming months may look like.

Our ability to focus, to feel comfortable around others, even to think more than a few days into the future, may diminish — with lasting consequences. But we may also feel the tug of a survival instinct that can activate during periods of widespread peril: a desire to cope by looking out for one’s neighbors.

“We are incredibly capable to adapt to any kind of situation,” Mr. Bozovic, now a professor of photography in Montreal, said. “No matter how bad it is, you adapt. You live your life as best you can.”