1. Michelle Trachtenberg took us back to 1999, with this photo of herself hanging out with Christina Aguilera.
2. Queen Latifah wished her friend Will Smith a happy birthday by remembering the time she guest starred on The Fresh Prince of Bel-Air.
3. January Jones continued to serve us some Regina George realness with this photo of herself at 17.
4. Paul McCartney rocked an pretty awesome beard back in 1968.
5. Colton Haynes bravely shared this high school photo of himself.
6. Speaking of high school photos, here's one of Sarah Hyland dressed up as an '80s aerobic instructor.
7. Dwayne "The Rock" Johnson once sported some pretty short shorts.
Broke & strugglin' to make it in the CFL, but... I never skipped leg day. #ThunderThighs #ShortsBeHugginABrutha #TBT
8. Pretty cool, Busta Rhymes hanging out with Tupac Shakur back in the day.
#TBT Me & Pac 90somethin'..
9. And finally, Tom Brady posted this spectacular photo of himself riding Space Mountain.
