1.In celebration of her mom's birthday, Kat Dennings shared this photo of her mom holding her as a baby in the late '80s:
2.Will Smith posted this photo of himself with his siblings in the late '70s, as well as a current one of them:
3.While Nicole Kidman posted this photo of herself in the mid-'70s, as well as one of herself today:
4.Reese Witherspoon shared this photo of herself and her daughter, Ava, on the set of Little Nicky in 1999:
5.Gal Gadot posted this photo Zack Synder took of her in 2014, during her camera test for Batman v Superman:
6.Viola Davis shared this stunning photo of herself from the 2010s:
7.Tom Felton posted this photo from his Harry Potter days — and I'm not going to lie, this does look like the cover art for a mixtape:
8.Julia Roberts posted this photo of herself and her mom in the early '70s:
9.Sarah Michelle Gellar celebrated the 28th anniversary of her first appearance on All My Children by posting this promo photo she took for the show:
10.David Beckham shared this photo of himself and his little sister in the early '80s, in celebration of her birthday:
11.In honor of Smokey Robinson's 81st birthday, Diana Ross shared this clip from when she inducted her fellow living legend into the NAACP Image Awards Hall of Fame in 2000:
12.Jane Fonda remembered when she accompanied her son, Troy Garity, to the Golden Globes in 2004. He was nominated for Best Actor Performance in a Miniseries or Television Film for the movie Soldier's Girl:
13.Lenny Kravitz shared this photo from when he was on his 1991 Mama Said Tour:
14.Paul McCartney remembered George Harrison on what would've been his 78th birthday by sharing this photo of the two of them in the late '60s:
15.Hillary Clinton threw back to her early '90s headband days:
16.Amy Sedaris remembered when she appeared in the "Apartment Hunters" episode of Broad City in 2014:
17.In honor of Josh Gad's 40th birthday, Luke Evans posted this photo of the two of them on the set of their 2017 film, Beauty and the Beast:
18.Hugh Jackman shared this hilarious video clip of himself and John Travolta performing "Summer Nights" while promoting their 2001 film, Swordfish:
19.And lastly, Betty White shared this video montage of her early '70s TV show Betty White's Pet Set, in celebration of it being released onto Amazon Prime Video: