Pavement Trajectories

Funny how when you walk down a busy street, pedestrian trajectories are 'just so'. It's like ants. There's a surprising lack of bumping into each other. And then, one day, an otherwise normal day much like any other, no hangovers or daydreaming, it suddenly goes wrong. Within a 5-minute period, I narrowly avoided three collisions. It wasn't even busy. Two people crossing my path (or - aha! - me crossing their's?) which forced me to slow down and speed up respectively, and the classic case when someone's coming straight for you and you each adjust your trajectory but still end up heading straight for each other. In the end we had to laugh and inched round each other as if we were on a cliff edge.