The puzzle of why there was a worldwide cascading abandonment of a hundred years of accumulated knowledge by scientific and policy advisers will occupy researchers for many years. The result is that old lessons are having to be relearned. Judging by the rush of studies now coming through to contradict key tenets of the 2020–22 narrative, there’s hope that the wall of silence rooted in groupthink and fear of consequences to career and reputation might have been irreparably breached.