In the minds of many Americans, Cinco de Mayo is an excuse for conspicuous inebriation masquerading as a cultural holiday. Often confused with Mexican Independence Day (which is actually Sept. 16), the celebration originated in California and Oregon among pro-Union Latinos during the American Civil War.

On May 5, 1862, the Mexican army defeated a much larger force of French invaders at the Battle of Puebla. While not a tactically significant victory, the unlikely defeat of Napoleon III's forces came to symbolize the triumph of democracy over monarchy and oppression. Latinos in the U.S. at the time celebrated Cinco de Mayo as anti-Confederate and pro-freedom.

So the holiday's provenance is on the side of the angels, but 150 years later, it's morphed into a garish display of cheap sombreros, fake mustaches and watered-down margaritas. The only region of Mexico that celebrates it is Puebla, and Mexican Americans rarely join in.

So what else has been masquerading as Mexican?

1. Hard-shell tacos

The guacamole you'll probably scarf down tonight is definitely Mexican—the avocado is indigenous to Mexico, Central and South America. But the lime juice that keeps it from turning brown isn't, at least not originally.

Limes were first cultivated in Persia and southeast Asia and brought to the Americas by the Spanish (along with smallpox), where they were quickly integrated into the local cuisine.

They grew well in the warm climate, and today, Mexico is the world's largest producer of limes.

Bonus facts: cilantro is also from Asia, and the wheat in flour tortillas is from the Middle East and Africa. But corn, tomatoes and chocolate are all Mexican.

6. Lupita Nyong'o

Just kidding, she's totally Mexican.

The winner of the Academy Award for her portrayal of Patsey in 12 Years a Slave was born in Mexico City, the daughter of a visiting Kenyan scholar. She holds dual citizenship in both Mexico and Kenya, studied at the Universidad Nacional Autónoma de México (also Hampshire College and Yale), and speaks fluent Spanish (also Luo, English and Swahili).

No wonder everyone's fighting over her.