When considering the lives of the rich and famous, it is always tempting to look for the secrets of their successes. So here's a brain teaser: what do the cook Julia Child, the novelist Gabriel García Márquez, the singer Taylor Swift, and Google's founders Larry Page and Sergey Brin all have in common?

The answer is that they all attended Montessori schools as young children. In the US, the schools' influence in the art and tech world has long been noted. But the reach of the educational method goes far beyond that. Indian independence leader Mahatma Gandhi was a fan, and described how children taught with it "felt no burden of learning as they learnt everything as they played".