It's hard to believe, but it's been almost 12 years since Laguna Beach, the MTV reality show that spawned The Hills and completely changed the world of reality television, first hit the small screen. While viewers may have initially been drawn to the shows for the beautiful castmates, luxurious locales, and never-ending drama, the real heart of them was the friendship between the female stars and all the life lessons they learned as they journeyed from high school into young adulthood. In honor of the upcoming 10th anniversary special of The Hills [1], keep reading to find out all the major life lessons we learned from watching both shows. And, of course, don't forget to check out what the cast members of Laguna Beach and The Hills are up to now [2]!

Don't Wait Around For a Guy

What Happens in Cabo Stays in Cabo

Take Good Care of Your Car

It's Always a Fashion Show

If Your Best Friend Hates Your Boyfriend, That's Probably a Bad Sign

It's About Quality, Not Quantity, With Friends

Know How to Spot a Weirdo

Just Don't Date Jason Wahler — Like, Just Don't

Even the Cute Guys Can Be Nasty When They're Drunk

Don't Play Around With Friendships

Don't Date Pretty Boys

It's Hard to Find a Cute White Dress

Remember the First Rule of Being a Good Friend

Know the Importance of a Well-Executed Cry

Know How to Make a Memorable Exit

Don't Date Men Who Accessorize More Than You Do

Best Friends Are Best Friends For Life

And, Finally, Don't Be the Girl Who Didn't Go to Paris