Right there and then I stopped assuming the vehicle in front would do as I would expect

I was coming up the east-bound slip road from the Croydon fire station roundabout onto the Croydon Flyover on my KLR600 back in the late '80s. At the very moment I looked back over my right shoulder to check for traffic on the flyover, the car I was following at some distance stopped as it reached the 'Give Way' line.

The flyover was clear, but when I turned my attention back to the road ahead I found a stationary vehicle in my path. Fortunately, my line was just to the offside of the car, which my leg missed by millimetres. Right there and then I stopped assuming the vehicle in front would do as I would expect, especially at a junction.