It's the 20th anniversary of 'Clueless' and we have fashion nostalgia.

It was the Mean Girls–equivalent movie of the ‘90s and today, cult classic Clueless officially turned 20 years old.

As if!

Read more: 17 things you didn’t know about 10 Things I Hate About You.

Loosely based on Jane Austen’s classic novel Emma, an entire generation of teenagers wanted to be besties with popular but naïve do-gooder Cher Horowitz (played by Alicia Silverstone), crushed manically on Paul Rudd and learned valuable advice from the 1995 movie that still holds true today.

For example, on dressing to impress:

Where’s my white collarless shirt from Fred Segal? It’s my most capable-looking outfit!

On wickedly-quick catty comebacks:

Amber: Was I the only one listening? I thought it reeked.
Cher: No, I believe that’s your designer-imposter perfume.

And on asylum seekers:

Like, right now for example, the Haitians need to come to America. But some people are all, 'What about the strain on our resources?'. But it’s like when I had this garden party for my father’s birthday, right? I said RSVP because it was a sit-down dinner. But people came that, like, did not RSVP. So I was like, totally buggin'. I had to haul ass to the kitchen, redistribute the food, squish in extra place settings. But by the end of the day it was, like, the more the merrier. And so, if the government could just get to the kitchen, rearrange some things, we could certainly party with the Haitians. And in conclusion, may I please remind you that it does not say RSVP on the Statue of Liberty.

And of course, who could forget the incredible style inspo we got from Cher’s 60 different outfits? Carefully crafted by her to-die-for computerised wardrobe?

But Clueless costume designer Mona May said Alicia, who was just 18 at the time, was more fashion victim than fashionista when it came to pulling off Cher’s designer dresses and preppy miniskirts.

“[Alicia] was really young, and I don't think she was really experienced with high fashion. When we brought all this crazy stuff, it was a little bit new to her,” Ms May told Yahoo at a recent screening of Clueless on Los Angeles.

“We almost had to educate her on how do you wear the clothes, how do you feel in the clothes? It's a whole different thing of running around with your dogs in your sweatpants, as she always does to this day.”

But Ms May said Alicia, who was famous for her appearances in Aerosmith music videos, captured Cher's innocence perfectly.

“Cher was never contrived, and I think Alicia's heart is open like that, so it was fun to play with the clothes and teach her to be the high-fashion maven.”

Alicia, who is now known for her vegan lifestyle, said she initially doubted whether she could play the high school queen bee, especially her outgoing personality.

“It was hard because there's a voice that comes with that that I didn't know I had to have. I was always sort of quiet and soft-spoken and in this she's sort of obnoxious and takes control,” the Blast From the Past actress told TODAY.

But the 38-year-old said all she had to do in the end was just believe "100 percent in the silly things that Cher believes in".

Which is your "classic" Clueless moment?

Tap the image for more 90's nostalgia; our favourite quotes from 10 Things I Hate About You.