Many of us dream about changing career in midlife but reason ourselves out of it on the basis that we can’t throw all that time and effort away, and that we’d be clueless in another vocation, anyhow – not to mention about 20 years behind everyone else.

But bestselling author David Epstein says we’re likely to thrive for the very reasons we fear we’ll fail. In Range: How Generalists Triumph in a Specialised World, Epstein studied the world’s most successful people – scientists, musicians, athletes...