Interesting likely-true thing: Cinco de Mayo is a minor holiday in Mexico commemorating the Battle of Puebla and wasn’t celebrated at all in the United States until the ’70s, when Mexican and Chicano student organizations were looking for a day to hold their large annual cultural events. Since Mexican independence day is September 16th, right at the beginning of the year, these organizations settled on May 5th, a date which gave them an entire school year to raise money and plan activities.
Years later everyone else decided that they like Corona and it became a thing in the US.