St Patrick's Day is a time when everyone brags about their miniscule Irish heritage and uses it as an excuse to wear Guinness hats and get drunk. Here are some facts you probably didn't know about this Celtic celebration.

1. The first St Patrick's Day celebration wasn't actually recorded in Ireland; it was in Boston, USA in 1737, which had a large Irish immigrant community that wanted to celebrate their heritage and identity.

2. St Patrick was actually born in Scotland or Wales, but was taken to Ireland as a slave and became a shepherd.

3. Around 13 million pints of Guinness will be drank worldwide today.

​4. St Patrick actually wore blue vestments. The colour green represents the season of spring and the shamrock, which Paddy apparently used to teach the Holy Trinity.

5. Even though modern celebrations of St Patrick's Day involve a lot of drinking, from 1903 until 1970 the pubs were closed for religious observance in Ireland - meaning everyone had to attend the Royal Dublin Dog Show for a drink.

6. Legend has it that old Paddy drove the snakes from Ireland - but the post-glacial Emerald Isle would never have been warm enough for the cold-blooded reptiles. It is said that the snakes were actually a metaphor for pagan priests.

7. There are 4.2 million Irish people in Ireland, but 34 million people of Irish descent living in the United States.

8. The chances of you finding a four leaf clover are 1 in 10,000. Soz.

9. Chicago dyes its river green on St Patrick's day using 45 pounds of vegetable dye. It usually lasts for about a week.

10. Leprechauns are usually depicted as jolly creatures, but they were actually quite mean. In an 8th century tale, they tried to drag King Fergus of Ulster to the ocean to drown him in his sleep until he kicked up a fuss. Then gave him the power to breathe underwater using herbs in his ears or one of their cloaks. This worked for every body of water except for one lake. Of course, that was the one lake in which he had to fight a sea monster, so he drowned. Unlucky.