Some people thought the world might end in 2012 because that was the last calendar year in the ancient Mayan calendar. The Mayan people lived in South America and made a relatively accurate calendar that extended to the year 2012. People thought that they had maybe predicted an apocalypse. Thankfully, they didn’t and the world kept going. 🙂 It’s hard to know why things happened in the past and why the calendar stopped then.