1. Lena Dunham reminded us what early '00s teen fashions looked like.
2. James Franco shared this late '90s pic of himself alongside his Freaks and Geeks co-star Jason Segel.
3. An intimate portrait of Wings-era Paul McCartney, taken by his late wife, Linda.
Paul by Linda taken in the south of France. #ThrowbackThursday
4. Katy Perry's TBT photo also happens to be the cover of her next single "Birthday."
In honor of #TBT may I present the cover of my NEXXXT single, BIRTHDAY
5. BFF's Candace Cameron and Andrea Barber (aka D.J. Tanner and Kimmy Gibbler) looked like late'80s perfection in their hats.
6. A stunning photo of a 19-year-old Kim Cattrall.
When ur 19 u can sit like that. #throwbackthursday On set of Scruples 1978. @KimCats2013 @SensitiveSkinTV
7. And a silly photo of Orange Is the New Black's Matt McGorry.
8. So cute: Elle Macpherson as a flower girl.
1970(ish)... Sheepish grinned flower girl at my aunt's glamorous wedding.. #throwbackthursday
9. January Jones looked adorable while sporting some really serious bangs.
10. Grizzly Bear's Ed Droste (bottom right) was clearly not having a good time.
11. Mayim Bialik dressed in her AYSO finest.
12. And finally, Joey Fatone shared this adorably awkward photo of NSYNC's early days. And all I have to say is: SO MUCH HAIR GEL.
@realjoeyfatone: #TBT the men that started it all with "I want U back" Denniz Pop and Max Martin