Bitcoin Pizza Day is celebrated every year on May 22 to mark the first real-world transaction using Bitcoin. On this day in 2010, a programmer named Laszlo Hanyecz paid 10,000 Bitcoins for two pizzas, which were worth about $41 at the time. This event is significant because it showed that Bitcoin could be used as a medium of exchange, not just a digital concept. Today, those 10,000 Bitcoins would be worth millions of dollars, making it one of the most expensive pizza purchases in history. Bitcoin Pizza Day is now a symbol of how far cryptocurrency has come since its early days.