"He was just an average, teenage kid when I first met him," Ronnie French, a family friend from Augusta, Kentucky, tells PEOPLE about the former Sexiest Man Alive. "He played basketball and baseball and tennis … Even though he was younger, he wanted to hang around with us older guys."
And turns out, the actor – who's engaged to British attorney Amal Alamuddin – has always been a prankster. "He joked around all the time, and he still does," says French, 67. "He's been like that all his life."
French and Clooney, 53, were both extras on the set of the miniseries Centennial, where the pals were "just thrilled we would get a role to play on TV."
And though the two are no longer in close contact, when Clooney makes it back home, it's as if no time has passed.