At the start of the pandemic, when downloadable data became available, I started charting it every day. The curves for many countries were uncannily exponential

At the start of the pandemic, when downloadable data became available, I started charting it every day. The curves for many countries were uncannily exponential. Of course I knew that those curves had to tip over at some point, but I decided that I would use the exponential growth curve as a baseline and watch for deviations from it. I told my friends: "I'll breathe a huge sigh of relief if this thing turns over before it's infected most of us." In fact it's probably hard to speculate why it turned over, but behavioral measures are probably an important factor.