Today, Sisterhood of the Traveling Pants star Amber Tamblyn turns 31, and with a new film on the horizon for the franchise, it's time to look back on all the memorable life lessons captured by the series. The upcoming film will be inspired by the final book by Ann Brashares, Sisterhood Everlasting, which came out in 2012. If the first two movies are any indication, the third installment will illustrate plenty of relatable truths about love, life, and friendship. Actresses Blake Lively [1], Alexis Bledel, and America Ferrera [2] starred alongside Tamblyn for both films, and while nothing's been confirmed, we hope to see them reprise their roles as Bridget, Lena, Carmen, and Tibby for the third movie, too. In honor of Tamblyn's birthday and the new Sisterhood of the Traveling Pants buzz, find out which Sisterhood of the Traveling Pants character you are [3] and take a trip down memory lane with 23 totally true facts found in the series.

Nothing beats a girls' trip.

When you have friends who feel like family, you hold onto them.

Especially if you share the same values.

Sure, sometimes you have to fend for yourself.

You do what you have to do to thrive on your own.

But life is easier when you have people to lean on.

The thing is, everyone has their fair share of insecurities.

And sometimes it can feel a little hopeless.

Life will throw you curveballs.

And relationships are complicated.

It can be tempting to run away when things get tough.

Or, you know, eat your feelings.

But sometimes there's a light (or a person) at the end of the tunnel.

You just have to push through.

And take a few risks.

And embrace a sense of adventure.

Sometimes you just have to learn to let go.

Don't be afraid to confront what's hard.

And don't be afraid to try something new.

If you follow your heart, things will work out.

And even if they don't, you still have your friends-turned-family.

And hopefully a good pair of jeans.

Honestly, when in doubt, just go to Greece. (That's the real lesson here.)