1.Mary-Kate and Ashley got the part of Michelle Tanner on Full House because out of the 20 babies that auditioned, they were the only ones that didn't cry.
2.The twins only appeared together on-screen in four episodes of Full House. In one particular episode, titled "Greek Week," Mary-Kate played Michelle Tanner's cousin Melina, and wore a black wig for the role.
3.At six years old, the twins didn't look so identical anymore and producers picked Mary-Kate for the role of Michelle Tanner. The girls insisted, though, that they still take turns playing the character.
4.Ashley said that their upbringing could be compared to the army because of how rigorous their schedules were.
5.The girls have been fashion fans their entire lives. Michelle Tanner's wardrobe on Full House was made up of a lot of designer clothes, "including Chanel and Marc Jacobs."
6.All that hard work and longevity has their company, Dualstar, rolling in the dough. It's said to be worth a billion dollars.
7.Mary-Kate is left-handed, while Ashley is right-handed.
8.While filming Full House the twins were losing their baby teeth, so they had to wear dentures so that Michelle Tanner would have a full smile.
10.Full House producers credited them as one person — "Mary-Kate Ashley Olsen" — in the show's first few seasons.
11.The twins ditched their high school prom because they were asked to host the 2004 season finale of Saturday Night Live.
12.They've spent so much time together that they can't remember specifically which memories belong to whom.
13.But despite them both spending so much time together, only one— Mary-Kate — was nominated in 2002 for a Daytime Emmy award. She was nominated in the Outstanding Performer in a Children's or Pre-School Children's Series category for her role in So Little Time.
14.Mary-Kate loves horses. She regularly rides and competes in the Hampton's Classic Horse Show, and in 2013 she won first place.
15.They started their fashion line The Row because Ashley wanted to make the perfect T-shirt.
16.Mary-Kate and Ashley share a lot of things with each other... including their star on the Hollywood Walk of Fame, which they received in 2004.