Get ready to chow down on sticky and sweet sandwiches all day long, because it's National Peanut Butter and Jelly Day!

While the origins of this holiday are unknown, it is certainly one worth celebrating. Of course, what better way is there to celebrate while eating your peanut butter and jelly sandwich, than with some PB&J trivia? Check out these seven fun facts about Peanut Butter and Jelly Sandwiches below, compliments of The National Peanut Board, Smucker's and Which Wich:

1. The first known reference to peanut butter and jelly being paired together on bread was back in 1901 in the Boston Cooking School Magazine of Culinary Science and Domestic Economics. The woman who wrote about it was named Julia David Chandler.

2. During World War II, both peanut butter and jelly were said to be a part of the United States soldiers military ration list.

3. In 1968, the J.M. Smucker Co. Introduced Goober to the world. The product, which features both vertical stripes of peanut butter and jelly in a jar, was marketed as a "sandwich in a jar."

4. The average American will have eaten more than 2,000 Peanut Butter and Jelly Sandwiches before graduating from high school.

5. Surprisingly, jelly is not the most common pairing with peanut butter. In fact, in a survey, only 49% of people agreed that peanut butter and jelly made for the best combo.

6. Peanut Butter packs a large amount of protein. In fact, vegetarians can get a complete serving of protein in one peanut butter sandwich on whole wheat bread.

7. Sandwich chain Which Wich made 26,710 peanut butter and jelly sandwiches in one hour back in 2015, setting the world record. They continue to sponsor and hold events related to the sandwich, including a current campaign called Project PB&J, where they encourage customers to #SpreadtheLove. Those who want to help only have to buy a Project PB&J sandwich at a participating store, and they'll give one each both within the local and global community. They can also purchase various products to donate a larger amount of money to the project.