Santa Claus
Santa performs at The Grove Christmas with Seth MacFarlane Presented by Citi at The Grove, Nov. 13, 2016, in Los Angeles. Charley Gallay/Getty Images for The Grove

In case you hadn’t guessed from the sultry tones of Mariah Carey once again soundtracking seemingly every store in the United States, the official lead up to Christmas is now very much underway. While it may seem that the Christmas season gets bigger and longer with each passing year, there are still some things about the holiday that many don’t know. These 12 should help get you started:

1. No, Santa Claus Isn’t Real; But Saint Nicholas Is
There isn’t really someone, other than perhaps your overly ambitious parents, who comes down your chimney to deliver presents. But the legend is modeled on a real person. Saint Nicholas was born in the third century in modern-day Turkey and established a reputation for generosity and secret gift giving. The name Santa Claus was born out of the Dutch Sinterklaas, which itself was derived from St. Nicholas.

2. A Real Santa Claus Would Have A Rough Night Delivering All Those Presents
The physics involved for one person delivering presents to every Christmas-celebrating child in the world in one night are truly mind-blowing. Many have actually crunched the numbers over the years, including Ethan Siegel for Forbes last year, who calculated that Santa would only get 223 microseconds to hit each of the estimated 500 million households. That doesn’t leave a whole lot of time for cookies and milk.

3. Advent Doesn’t Actually Start On Dec. 1 – Most Of The Time
While many people have likely tucked into their first chocolate of their advent calendar on Thursday, advent, as the season leading up to Christmas is known in Christian tradition, actually began this year on Nov. 27. It always begins on the fourth Sunday before Christmas.

4. Her 'True Love' Gives Her A Lot Of Gifts
The famed English Christmas carol “The Twelve Days of Christmas” dates back more than a century. If you add up all the gifts that “my true love sent to me” over the course of the 12 days, it would total 364. A pretty happy Christmas, indeed.

5. The Traditional Christmas Colors Date Back Centuries
The use of red and green at Christmas may date all the way back to the colors used on screens to separate parishioners and the priest and altar in churches during the Middle Ages, according to one Cambridge University researcher. Green is, of course, also the color of evergreen trees used as Christmas trees and symbolize life and rebirth. Red can also symbolize the blood of Christ. Another color of Christmas, gold, represents one of the gifts given to baby Jesus by the three wise men.

6. Christmas Trees Began In Germany
The tradition of Christmas trees is believed to have originated in Germany in the 16th century. Many credit the man who led the Protestant Reformation, Martin Luther, with being the first to put lights on an evergreen tree for Christmas. Luther is said to have been captivated by stars twinkling above evergreen trees while walking home one winter evening.

7. Christmas Wasn’t Always Celebrated On Dec. 25
No date for Jesus’ birth is given in the Bible and it was first thought to have occurred on Jan. 6. It wasn’t until the 4th century that the celebration moved to Dec. 25 and was later officially decreed as a holiday by Pope Julius 1. The date is thought to have been chosen because of its place among other Pagan holidays, in particular, the winter solstice.

8. Celebrating Christmas Was Once Illegal In The U.S.
The puritans who first settled in the United States were no fans of Christmas. So much so in fact that from 1659 to 1681, celebrating Christmas could leave you liable to pay a fine of up to five shillings. Showing what they thought of the tradition, the first session of Congress was actually held on Christmas Day, 1789. It wasn’t until 1870 that Congress actually proclaimed the day a holiday.

Rockefeller christmas tree
The Christmas tree stands lit after the lighting ceremony for the 84th annual Rockefeller Center Christmas Tree at Rockefeller Center in Manhattan, New York City, Nov. 30, 2016. Reuters/Alex Wroblewski

9. Rockefeller Christmas Tree Is Not The World’s Largest
The Christmas tree at New York City’s Rockefeller Center, which was lit for this year on Wednesday, may be the world’s most famous, attracting tens of thousands of visitors from across the globe, but it is not the world’s biggest. The current Rockefeller tree is said to be around 75 feet tall, which falls way short of the current world leader, which resides in the German city of Dortmund and stands 148 feet high.

10. Coca-Cola Really Has Had A Major Impact On Christmas
For some, the Christmas season really starts when that first Coca-Cola commercial comes on the television. However, the beverage company’s influence over the holiday stretches beyond its catchy tune. The modern-day image of Santa Claus with his jolly round tummy and red suit was crystallized by the character which first appeared in Coca-Cola commercials in 1931.

11. Reginald The Red-Nosed Reindeer?
The character of Rudolph the Red-Nosed Reindeer dates back to a 1939 booklet written by Robert L. May, before it was turned into the famous song by Johnny Marks 10 years later. But the leader of Santa’s sleigh almost wasn’t Rudolph at all, with Rollo and Reginald two of the other names initially considered.

12. For Many, The Real Celebration Is Christmas Eve
In a number of countries around the world, including much of Central Europe and Latin America, the major festivities, including the opening of presents, actually occur on the night before Christmas in the lead up to midnight.