There is something remarkable about the minutiae of all these ordinary lives in a seemingly ordinary week persisting in the human record for almost two centuries. When that chemist’s son spooned out his sweet pudding, he couldn’t possibly have imagined that the details of his meal would be a matter of interest to anyone else in Victorian London, much less citizens of the twenty-first century. This is one of the ways that disease, and particularly epidemic disease, plays havoc with traditional histories. Most world-historic events—great military battles, political revolutions—are self-consciously historic to the participants living through them. They act knowing that their decisions will be chronicled and dissected for decades or centuries to come. But epidemics create a kind of history from below: they can be world-changing, but the participants are almost inevitably ordinary folk, following their established routines, not thinking for a second about how their actions will be recorded for posterity. And of course, if they do recognize that they are living through a historical crisis, it’s often too late—because, like it or not, the primary way that ordinary people create this distinct genre of history is by dying.

Steven Johnson in Ghost Map – Chapter “Eyes Sunk, Lips Dark Blue” (2006)