A very experienced ex-mil pilot (Spits, Vampires, Meteors, Vulcans etc. etc.) friend of mine once told me a tale of when he was flying in a Lanc.
They were on a cross country nav exercise. The navigator instructed the pilot to turn 90 degrees right, then soon after 90 degrees left, then 90 degrees left again and finally 90 degrees right.
The pilot said to the navigator, "What was all that about?"
The navigator replied, "I've just navigated you around a bean, I dropped my lunch on the chart!"