You know I only realised shortly before Christmas that 20,000 leagues is 60,000 miles, some 7.5 times greater than the diameter of the earth.

Clearly I'd never read the book or seen the film or else I'd have realised it was 20,000 leagues travelled beneath the oceans around the world. But up until that point I'd just thought of it as a depth.

Anyone else learn anything they should have already guessed?