“After receiving the Nobel Prize in Physics in 1918, Max Planck went on tour across Germany. Wherever he was invited, he delivered the same lecture on new quantum mechanics. Over time, his chauffeur grew to know it by heart.
“It has to be boring giving the same speech each time, Professor Planck. How about I do it for you in Munich? You can sit in the front row and wear my chauffeur’s cap. That’d give us both a bit of variety.”