There was a world before COVID-19.

People went to restaurants without thinking about whether the tables were too close together.

People entered crowded concerts.

People travelled without constantly checking restrictions.

Children went to school.

Friends shook hands.

Families gathered.

Airports were busy.

Cinemas were full.

Nobody needed a QR code to explain whether they were allowed to enter an ordinary place.

Then, remarkably quickly, the normal world stopped.

The change was not gradual.

For billions of people, the year 2020 became a dividing line.

Before.

After.

The World Health Organization declared COVID-19 a pandemic on 11 March 2020, after the outbreak had spread internationally. Governments responded with combinations of movement restrictions, business closures, school closures, testing, quarantine, masking, vaccination campaigns and other public-health measures. (World Health Organization)

The vocabulary of ordinary life changed.

Lockdown.

Quarantine.

Social distancing.

PCR.

Variants.

Flatten the curve.

Essential worker.

Remote learning.

Zoom.

Vaccination certificate.

Isolation.

These words moved from specialist terminology into everyday conversation.

But something else happened.

People began questioning things they had previously taken for granted.

How much authority should governments have during an emergency?

How much freedom should individuals surrender for collective protection?

How much trust should be placed in institutions?

How much information should platforms remove?

How should scientific uncertainty be communicated?

And when an emergency ends, which emergency habits disappear?