In his autobiographical novel Boyhood, Leo Tolstoy describes his youthful joy in philosophical abstraction: “I frequently imagined myself a great man, who was discovering new truths for the good of mankind, and I looked on all other mortals with a proud consciousness of my dignity.” His euphoria didn’t last. “Strange to say,” he wrote, “whenever I came in contact with these mortals, I grew timid.” Soon he was “ashamed of every simplest word and motion.”

Archaeologists in France discovered in 1865 a Stone Age human skull with a hole sawed in it. They believed it had served as a drinking vessel; one wrote the hole was “expressly made for the application of the lips.” But later study by an anatomist proved this to be incorrect: the skull was actually evidence of ancient brain surgery.

A scholar in Peking contracted malaria in 1899 and was given medication with an ingredient labeled “dragon bones.” The bone chips, he found, were inscribed with writing dating back to China’s second dynasty. Thousands more were uncovered in the decades following; many of these “oracle bones” had inscriptions recording celestial events, which scientists have since used to calculate changes in the length of an earth day and in the rate of the earth’s rotation.

In the 1860s, toward the end of his life, “father of computing” Charles Babbage “never abstained from the publication of his sentiments when he thought that his silence might imply his approbation,” wrote his friend Harry Buxton, “nor did he ever take refuge in silence when he believed it might be interpreted as cowardice.”