Never heard of #ThrowbackThursday? To put it simply, it's an excuse to relive some of your favorite memories...and, of course, share them for all the internet to see!
Everyone from Jessica Alba to Mario Lopez to Naya Rivera have celebrated #tbt with hilarious childhood pictures. Check out the 25 best celebrity throwbacks:
Next Slideshow: Demi and Selena: BFFs Throughout The Years
Did you know Nicole Richie was an aspiring violinist? She posted this adorable picture with the caption: “Dreams DO come true. Well, this one didn’t, but a lot of them do.”
How unfair is this? Even as a child, Gisele was drop-dead gorgeous.
Selena is all smiles next to her friend, who happens to be sporting a Barney shirt! Coincidentally, Selena’s first job was a role on Barney and Friends. “No matter who you are, where you are from and what you want to do with you life,” Selena wrote, “Please never give up. I love you all for believing in me.”
Wilmer Valderrama posted this picture of him and his familia in Venezuela in 1988. The cutie was just eight-years-old! (Plus, how stunning is his mamá?!)
Hilarious! Jessica Alba posted this picture of her goofing off with her primos during a camping trip.
Wow, remember this impressive Victoria’s Secret lineup? The Brazilian beauty posted this picture of her with Heidi Klum on the VS yacht.
Actress Gina Rodriguez posted this adorable picture of her and her papá! We just want to squeeze those chubby cheeks!
Before he was a famous actor and heartthrob, Mario Lopez was a kid champion...in wrestling! Even at six-years-old, Lopez already had the beginnings of a serious set of guns.
That gorgeous blonde is none other than Black Eyed Peas frontwoman, Fergie!
Believe it or not, that little girl clutching her doll is Fast and Furious star Michelle Rodriguez!
The American Idol judge posted this picture with the incredibly appropriate caption: “Recordando los años dorados.” The golden years, indeed...
Seriously? Alessandra Ambrosio has always been drop-dead beautiful...even as a baby-faced teen!
Adrienne Bailon, along with her sister and a friend, look chic and stunning in these incredible flapper costumes!
Oh, man, that oversized sweatshirt. We’re having serous 90s flashbacks over here...
And the winner for cutest kid EVER goes to...
Woah! We hardly recognized the cubano without his sunglasses on!
Becky G posted this picture with the hilarious caption: “#tbt to my Dora the explorer days. Haha”
Teen Wolf star Tyler Posey posted these pictures of him, his father, and his brother. Wow, that’s one attractive family…
We can’t get over how cute Sara Paxton was as a child! She posted this picture of her dressed up as a kitty-cat with the caption: “Later that day, I redrew this with sharpie.”
Long before Machete Kills, Alexa Vega and Robert Rodriguez collaborated on the Spy Kids trilogy!
Actress Francia Raisa and her sister, Italia, pose with these playful leis on a Hawaiian vacation.
Que preciosa! Christian Serratos clutches her abuela in this adorable throwback.
“#ThrowbackThursday Eatin’ ice cream like a boss in ’96,” Victoria Justice posted on Instagram.
How 90s is that outfit? The Fosters star Cierra Ramirez poses for the camera in this adorable throwback.