Every year Americans flock to Irish pubs, drink green beer ( or Guinness) and eat some corned beef but very few have any idea what the original holiday is actually about. We compiled a list to help brief you on the true meaning of St. Patrick’s Day with these fun facts so grab a pint and have fun.
1) We Really Should Wear Blue
Saint Patrick himself would have to deal with pinching on his feast day. His color was “Saint Patrick’s blue,” a light shade. The color green only became associated with the big day after it was linked to the Irish independence movement in the late 18th century.
2) Saint Patrick was British
Although he made his mark by introducing Christianity to Ireland in the year 432, Patrick wasn’t Irish himself. He was born to Roman parents in Scotland or Wales in the late fourth century.
3) The Irish Take St. Patrick’s Day Seriously
As you might expect, Saint Patrick’s Day is a huge deal in his old stomping grounds. It’s a national holiday in both Ireland and Northern Ireland.
4) It Used to Be a Dry Holiday
For most of the 20th century, Saint Patrick’s Day was considered a strictly religious holiday in Ireland, which meant that the nation’s pubs were closed for business on March 17. (The one exception went to beer vendors at the big national dog show, which was always held on Saint Patrick’s Day.) In 1970, the day was converted to a national holiday, and the stout resumed flowing.
5) There’s a Reason for the Shamrocks
How did the shamrock become associated with Saint Patrick? According to Irish legend, the saint used the three-leafed plant as a metaphor for the Holy Trinity when he was first introducing Christianity to Ireland. 
6) There’s No Corn in that Beef
Corned beef and cabbage, a traditional Saint Patrick’s Day staple, doesn’t have anything to do with the grain corn. Instead, it’s a nod to the large grains of salt that were historically used to cure meats, which were also known as “corns.”
7) The World has Racked up Quite a Bar Tab
All of the Saint Patrick’s Day revelry around the globe is great news for brewers. A 2012 estimate pegged the total amount spent on beer for Saint Patrick’s Day celebrations at $245 million. And that’s before tips to pubs’ bartenders.
8) It Could have been St. Maewyn’s Day
According to Irish legend, Saint Patrick wasn’t originally called Patrick. His birth name was Maewyn Succat, but he changed his name to Patricius after becoming a priest.
9) There are no Female Leprechauns
Don’t be fooled by any holiday decorations showing lady leprechauns. In traditional Irish folk tales, there are no female leprechauns, only nattily attired little guys.
10) Guinness sales soar on St. Patrick’s Day.
Recent figures show that 5.5 million pints of the black stuff are downed around the world every day. On St. Patrick’s Day that figure is doubled.
11) St. Patrick is a hero in Ireland.
There are about 60 churches and cathedrals named for him in Ireland alone. One of the most famous cathedrals is St. Patrick’s Cathedral in Dublin. These grounds bear the mark of the place where St. Patrick baptized his converts.
Fact Sources: http://mentalfloss.com/article/55599/15-delightful-facts-about-saint-patricks-day,