On 16 June 1904, a young James Joyce went for a walk with Nora Barnacle through Dublin. That single date became the setting for Ulysses, one of the most experimental novels in English literature, and gave rise to Bloomsday, an annual celebration now observed worldwide. The same date saw LaMarcus Adna Thompson open America’s first commercial roller coaster at Coney Island in 1884, launching the modern amusement park industry. In 1961, ballet dancer Rudolf Nureyev made a dramatic defection to the West at a Paris airport, beginning a legendary career but losing the ability to return home. And in 2010, Bhutan became the first nation to ban tobacco sales entirely. From literary romance to Cold War drama, 16 June has been a day for unexpected leaps and quiet revolutions.