Learner K. had a strange habit. I would pick her up for her lesson, no problem. We’d drive from her house onto the main road and accelerate normally up to 40 kilometres per hour. At this speed, however, she would take another three kilometres to reach 50 kilometres per hour.

At first I thought nothing of it. When she did this on her next lesson, I started wonder, why is she confident driving up to 40 kilometres per hour, then takes ages to reach 50?

The third time she again applied her strange accelerating method, I looked up and saw what the problem was: The numbers on the sign – Bus stop 40, Bus Stop 41, Bus Stop 42…