21 years has passed since this classic TV show aired its first episode titled, “The One where Monica gets a Roommate.” Ever since, it’s comedic timing, perfectly set NYC location, and stellar cast has brought us all laughs, tears, and a whole lot of life lessons. Here’s 21 things "Friends" has taught us over the past two decades:

1. Old videos will always resurface.

The prom video, where Ross decides to step in as Rachel’s date, is overshadowed by “fat Monica” and “pre-nose job Rachel.” Trust me, it’s hard not to look away.

2. Actually say the girl your marrying’s name at the alter.

When Ross utters Rachel’s name during the wedding ceremony for him and Emily, things get awkward really fast. Remember guys, practice makes perfect!

3. Never propose at a restaurant.

When Chandler finally gets the guts to propose to Monica in season six, Richard shows up, ultimately killing the moment. Chandler is thrown off and ends up not proposing that night. Instead, Monica and him propose to each other in their romantically lit apartment.

4. Always label your food when leaving it in the work fridge.

Because you never know who might eat it. When Ross’ boss eats his, after Thanksgiving sandwich, he causes a scene by yelling at his boss and ends up fired.

5. Don’t go to China with your new girlfriend.

Ross goes to China with Julie right when Rachel is realizing that she’s in love with him. Thank god he comes home soon enough and they start their jobs as one of the best couples in T.V. history.

6. Try not to get married in Vegas.

Ross and Rachel learned the hard way when they got married, for the second time, during a drunken night in sin city.

7. Cheesecake is delicious.

Remember that episode where Rachel and Chandler fight over Cheesecake crumbs?

8. Never Forget old dance routines.

You’ll never know when you need them. On Dick Clark’s New Years Rockin’ Eve taping, Monica and Ross pulled out a dance they made up in middle school.

9. Don’t get stung by a jellyfish.

Or else Joey might have to pee on it.

10. Stay away from Spray Tans.

Orange is not the new black. Especially when you’re Ross and don’t understand how to use the manual machine.

11. Find your lobster.

Phoebe likes to remind Ross and Rachel that they’re each others lobsters; once they mate, they’re together for life.

12. Always measure your furniture before you take it home.

There have been countless Friends episodes where people are struggling to get tables, chairs, and couches up the narrow, windy, NYC apartment stairs. Save yourself the trouble and higher a moving company, or better yet, make sure it fits first.

13. It’s okay to “bro” out.

Picture Phoebe, Rachel, and Monica chilling on the couch in their wedding dresses. But how can you forget them each drinking a beer with a bowl of popcorn in their laps? Even though we are ladies, it’s okay to chill like the dudes once in a while.

14. Don’t write a seven-page explanation letter.

Rachel puts Ross to sleep with this one.

15. Never bet your apartment.

When four members of the group play a game about who knows whom best, Monica and Rachel put their apartment on the line. They lose, of course, to Chandler and Joey.

16. To make a baby laugh sing “Baby Got Back.”

Sir Mix-a-Lot would definitely approve. Even baby Emma loves listening to both Ross and Rachel sing about their love for big butts.

17. Ditch the leather pants.

Ross gets stuck in his leather pants in a lady friend’s bathroom. They then shrink due to the amount of sweat he’s producing. Save yourself the embarrassment.

18. Don’t go to Barbados if you have frizzy hair.

Monica’s usually well-kept locks were looking like a lions mane during this episode. Avoid being the pun of everyone’s jokes and don’t forget to pack some hair spray.

19. If you’re on a break, that means no sleeping around!

Ross really messed up when he slept with the lady at the bar after Rachel said they should go on a break. This turned into the debate of the century that still has no definite answer. If you never want to do it, then don’t just don’t do it.

20. Thanksgiving is the best holiday.

Even though I disagree, it’s clear to the friends that Thanksgiving is the holy grail of Holidays. They even devote an entire episode, “The One with All the Thanksgivings,” to their special holiday transitions.

21. Friends are forever.

Through the past 21 years we have learned so much from all of the six friends. Not only have they taught us valuable life lessons, but they have also been there for us through it all.