If you're one of the many people who turned the big 4-0 this year, you're not alone. This Is Us costars Milo Ventimiglia [1] and Justin Hartley both hit the big milestone this year, as well as musicians Kanye West [2] and Chris Martin [3]. In addition to sharing the same birthday, John Cena and Kal Penn also turned 40 along with Tom Brady [4], Jessica Chastain, and Liv Tyler [5]. If we didn't know any better, we'd say these stars have found the fountain of youth.