Mary-Kate and Ashley Olsen are a '90s staple! We grew up with them, and we now feel like they ditched us since they fell off the face of the Earth. The twins ruled the world and were brilliant at it, now, we barely see photos of the fashion icons. Millennials are certainly having a hard time coping with their mysteriousness.

And because we saw them grow up in front of our very eyes in the limelight, we think that we know everything about them. To our dismay, however, there are quite a few bizarre secrets about the duo that make no sense and facts that were kept hidden for some odd reason. We know that Mary-Kate and Ashley, and even their other sister Elizabeth, who is also an acclaimed actress, are not like the rest of us. So, to help with the Olsen withdrawal, we thought we'd delve into their hidden lives and share some interesting facts about the Olsens.

20 The Twins Do Not Like Dealing With People

Why have the twins ghosted us? After dealing with intense fame for years since they began their lives in the limelight, the twins made changes. Both Mary-Kate and Ashley find that being around people is now an unpleasant experience for them.

The twins want to gain back all the space and freedom they missed out on growing up.

19 Mary-Kate Was One Of The Last People To Date The Late Heath Ledger

Before Mary-Kate walked down the aisle, she was romantically involved with the late actor who played the Joker.

Many were not aware of their precious relationship until Ledger’s unfortunate passing. Why? Ledger’s masseuse first contacted Mary-Kate with the news. Mary-Kate was involved in the intense investigation, that went on until 2008.

18 The Twins Were Credited As One Person

As children, we rushed home to watch the infectious Michelle Tanner on television because she was like our bestie. Although as children we did not pay attention to the credits, oddly enough, the twins, who are their own individuals, were credited as "Mary-Kate Ashley Olsen."

This was done to benefit producers, who did not want the live audience to know they were using two actors for the same part.

17 Mary-Kate Had The Strangest Wedding Ever

In November 2015, Mary-Kate got hitched to billionaire Olivier Sarkozy, but the nuptials were kept on the DL. Accustomed to lavish celebrity weddings, when news broke of Mary-Kate’s wedding, we were stunned to find out the celebration was entirely private; there were no more than 50 guests.

What was odd? The tables had "bowls filled with cigarettes, and everyone smoked the whole night," according to Page Six.

16 Also, The Twins Are Not Identical

They have fooled us all along! The twins, who have looked identical from the moment we were introduced to them on Full House, are fraternal twins.

The producers of the cult classic were able to notice some differences, and apparently, some fanatical fans of the duo can tell them apart, too.

15 Ashely Was A Victim Of Lyme Disease

In 2015, Ashley was fighting Lyme disease, and it took a toll on her life. The debilitating bacterial illness was caught in its very late stages, and the ticks underneath her skin caused unbearable pain in her skin and joints.

The delicate star took time away from the “lyme-light” and work as it also attacked her heart and nervous system.

14 Imagine Mary-Kate As A Stepmother, Well, She Is One

Mary-Kate’s beau, Olivier Sarkozy, has two children from his previous marriage. When she signed on the dotted line, she immediately became a stepmom.

Oddly enough, Julien and Margot, have a stepmom who is only slightly older than they are; MK is 32 and the kids are teens.

13 The Twins Wore False Sets Of Teeth For Quite Some Time

Full House had both Mary-Kate and Ashley alternating and playing the role of Michelle Tanner. However, that is not the only thing they both had to alternate.

Turns out, to play the role of a little girl in her early school years, they had to, as toddlers, wear a set of dentures. That explains the flashy smile!

12 Mary-Kate Had Her Own Share Of Battles

Being a child star has its downsides, which is probably why Elizabeth Olsen only made her debut later. Mary-Kate was no stranger to the spotlight, and in later years, it led to addiction.

Of the two, Mary-Kate was the half of the twin duo that fell deeper into the dark hole known as substance addiction.

11 PETA And The Olsen Twins Do Not Get Along

Why does PETA dislike the fashionistas? Because their clothing line, The Row, manufactures many fur products. PETA took the opportunity several times, on their blog, to share their dislike for the twins, who use the skins of animals.

The twin style icons have a love for fur, and so, PETA deems them pesky.

10 Ashley Had Surgery That Went Wrong

A surgery gone wrong is the nightmare of many. Well, that nightmare turned into a reality for Ashley, when she got a facelift. Days after the plastic surgery was done, her face began to swell and blacken – not normal, right?

Poor Ashley had a condition known as necrosis and had to undergo oxygen therapy.

9 The Twins Refused To Be In Fuller House

Neither Mary-Kate nor Ashley accepted the invitation to return for the Netflix revival series. The twins did not appear in front of the camera for years, so we assumed they would’ve taken the opportunity to get back in the vibe.

Instead, that is the exact reason, Ashley explained, that they did not want to act again. She added that it would make them uncomfortable, too.

8 The Twins Are Strangers To Online Shopping

Considering today's modern shopping world, fashion moguls are not fans of online shopping. Is that not odd considering online shopping means they can avoid dealing with people?

Ashley admitted to The New York Times that she has never purchased anything online, while Mary-Kate did buy something in an online auction once.

7 Social Media Isn’t Their Thing

Social media, like online shopping, is a big no-no for the twins. The twins have stuck to their guns since they have wanted to remain out of the spotlight.

Ashley explained that their lack of presence is because "[they've] never been connected to [their] fans in that way" and "[they've] stayed quite sheltered in that sense," as Cheat Sheet reports.

6 The Twins Tried To Look Different For Years

We still have a hard time distinguishing the gorgeous duo, even when/if they switch things up.

Ashley already decided to dye her locks a sultry deep brown, and Mary-Kate did some surgery. One guaranteed way to tell them apart? Ashley beats her twin sister by an inch.

5 And Apparently, They Have A Sixth Sense

What happens when twins are inseparable? In the case of Mary-Kate and Ashley, a sixth sense was developed. Because of that, until this day, the twins have a hard time separating their memories - how strange is that?

According to Vogue, in an interview the twins revealed an interesting fact to ponder on, saying that they "have a shared memory."

4 There Was An Art Exhibition Dedicated To Them

The twins have kept their lives low-key for over a decade, but two comedians decided to dedicate an entire museum to the "hidden" public figures.

According to Factinate, the curators were so fascinated by how the twins managed to escape the spotlight, that they set up an exhibit in NYC to show that off.

3 Mary-Kate Truly Embraces Her Body

Although Mary-Kate has a fabulous shape, that she keeps up by running daily, she adores her body more than most.

Mary-Kate has openly admitted that she overly enjoys running around in the buff – or in her birthday suit. The only thing she keeps on her is her beloved jewelry.

2 Prom? They Skipped That

The child stars did attend school, despite their fame and fortune, but when it came to prom, they could not have been bothered.

As teens, we all looked forward to prom night, but that never phased the twins, as they preferred to read monologues and hosted the season finale of Saturday Night Live.

1 Elizabeth Olsen Has A Thing For Auditioning

Most A-listers get nervous during auditions, but Olsen remains cool, calm and collected. That is completely odd considering how nerve-wracking auditions are.

Instead, this Olsen twin gets a kick out of auditioning and it actually soothes her. Elizabeth told Casting Frontier, "I really actually enjoy auditioning.”

Sources: Page Six, Vogue, The New York Times, Grazia, Casting Frontier