For me, the best thing in this week’s ultra-lite BMJ is this beautifully clear and logical editorial from New Delhi about lactose intolerance, a common problem in both children and adults with a large and often confusing literature. This piece makes it all add up and also tells you how to manage it.

I think that of all the numerous examinations I took in my earlier life, the driving test was the one I hated most. Yet almost anyone can learn to drive a car, and after the recognised onset of dementia it takes three years before there is a substantial rise in the accident rate. It seems that when we’ve been driving for decades, we do most of it on autopilot. So although people with a new diagnosis of a dementing illness are required to report it to the DVLA, they are often able to keep their licence for a year or two. The dissociation between driving and cognitive ability applies at the other end of the scale too. Wolfgang Pauli was among the most brilliant minds during the golden age of particle physics. He predicted the existence of the neutrino in 1929 and just missed seeing the first neutrino detected in 1959. He took 100 driving lessons but was still famously incapable of driving in a straight line or stopping at lights. His quantum physics colleagues said that his driving was a good illustration of the Principle of Uncertainty.