In 1929, a 25-year-old German surgical intern named Werner Forssmann wanted to prove you could thread a catheter into a living human heart. His boss forbade it. So Forssmann tricked a nurse into helping by telling her he'd do the experiment on her. When she lay down on the table, he strapped her arms down, then anesthetized his own arm and threaded the catheter into his own vein instead. He released the furious nurse, walked down to the basement X-ray room with the tube dangling from his arm, positioned a mirror so he could watch the fluoroscope, and pushed the catheter the rest of the way into his heart. He was fired. Twenty-seven years later, he won the Nobel Prize.