31 Things Mary-Kate & Ashley Taught Us

When Mary-Kate and Ashley Olsen appeared on Ellen on Friday, it was a big deal. The world's most famous twins hadn't been on TV together since 2010, leaving a generation of fans to rely on tabloids and fashion show photos to keep track of them. But as great as it was to see Mary-Kate and Ashley on TV again, it only reminded us that they're all grown up, just like the rest of us. So when you're missing the good old days of the 90s, when the color-coordinated twins would travel the world, solve mysteries, and throw great parties, you're better off revisiting their old classics. It turns out, you might actually learn something.

Those old Mary-Kate and Ashley movies are filled with important life lessons. You might've picked some up without even realizing it, after watching Passport to Paris or The Case of the Logical I Ranch for the hundredth time. But if you need a refresher course, you're in luck. Many of the movies are available in full online, thanks to YouTube user MaryKateAshleyFans. If you don't have time for an Olsen marathon, however, don't worry. We've compiled some of the best things that Mary-Kate and Ashley taught us.

1) Important Conversations Require Hands-Free Communication

The original Bluetooth.

2) When You Don't Have A Top Handy, A Bandana Will Suffice

3) McDonald's Will Always Be There For You

Even in Paris.

4) This Is How To Be Really, Really, Really, Unbelievably Scary

5) Billboards Are The Original (And Best) Dating App

As an added bonus, they're really easy to customize if you have the proper colored overalls.

6) What True Love Is Supposed to Feel Like

7) There's A Difference Between VHS Cases

Want a quick party or mystery? Go for the cardboard-covered tape. Have time for a full-length movie? Plastic it is.

8) How to Pluralize Words—Sort Of

9) Never Trust Megan Fox

10) The Right Way to Apply Lipstick

11) The Difference Between French Girls and American Girls

Well, technically Jean taught us that, but it still counts.

12) Pigtails Make the Best Beach Hair

13) Escargot is Gross

14) No, Seriously.

15) A Lady Puts Her Hand on Her Head Before Fainting

16) The Best School-Appropriate Form of Revenge

17) When a French Guy Offers to Whisk You Away on a Moped, You Say Yes

18) And Seal the Deal Before Coming Back to the U.S.

19) Ice Cream Sundaes Can Bring Up Painful Memories

But only if your family likes to share one sundae with each person getting their own topping.

20) Arguments Can Be Adorable

21) Most Destinations Are About A 15-Minute Bike Ride Away

At least, according to their trusty atlas.

22) Your Closet Should Reflect Your Personality

23) Even Movies That Are Really Giant Hotel Commercials Can Be Good

Did anyone else beg their parents to go to The Atlantis after seeing Holiday in the Sun?

24) The Best Matching Outfits Reverse Colors

25) And That Includes Accessories

26) It's Polite to RSVP

If it's up to me.

27) Blow Dryers Can Be Used as a Weapon, When Necessary

28) Always Fully Commit to a Theme

29) When Selling a Sibling, Be Prepared to Reduce Prices

30) Always Stick Up for the People You Care About

31) Most Importantly, Pizza is Delicious, Spelled P-I-Z-Z-A, and Best When Customized

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