Heroes now come pumping 56-inch chests, their stories embellished and amplified over multiple platforms. Now imagine an old, grey-hair gentleman, doddering around at home, shuffling through old memories, reluctantly bringing to light a story that needs to be told, hoping the focus will not be on him. That is what makes the little-known heroism of Nicholas Winton, an English stockbroker who played a key role in rescuing 669 children of largely Jewish descent from Prague just before Hitler started World War II, so special. Even the British only discovered him 50 years later, in 1989, when his story made it...