I’m writing this on St. Patrick’s Day in New York City, but there’s no parade, and on streets proudly teeming with Irish pubs, not one is open.

Pubs, restaurants: After hurricanes, as we sift through the wreckage and commence the repairs, we’re typically encouraged to flock to them, both to bolster local businesses and reclaim a sense of normalcy.

But normalcy is the enemy in this pandemic. We have to behave abnormally to reach the far side of it. As my colleague Michelle Goldberg recently wrote, “This mass withdrawal is like social chemotherapy, damaging the fabric of our communal life while trying to save it.”

On Monday I spotted a friend on the street, and we walked hurriedly toward each other, propelled by the human instinct for connection. About four feet from her, I abruptly stopped, the siren of science suddenly blaring in my head. But she kept advancing, and I was paralyzed: Dare I correct and possibly sadden someone whose error was possibly a sign of how sad she already was?

I did step slightly backward, and she seemed to register that, ending up maybe two and a half feet away: still too close, but less close than she might otherwise have been. We silently established some physical truce there. The etiquette of this pandemic is unwritten, and it’s brutal.

In the wake of Sept. 11, many of us sought to counter the economic toll by patronizing the kinds of businesses in New York and Washington that were most affected. That’s tougher with this pandemic. The most affected business are the ones that are shuttered, and our interactions with them can’t be transferred entirely to the virtual realm, though I’m consoled somewhat to see movements to purchase gift cards redeemable for restaurant meals, movie tickets and such at some future, post-pandemic point.

There will be such a point, right? We’ve been given no timeline, and that’s another special challenge of this crisis. It’s rolling rather than fixed, diffuse instead of discrete. It resists the drawing of any parameters around it. We have no idea what will ultimately be asked of us, so we can’t know what new emotional muscles to build, how strong they must be and what pace to take.