Billy Bob Thornton recounted a surprising moment when Johnny Cash contacted him by phone seeking an autographed copy of the Oliver Stone thriller U-Turn. Despite playing only a minor mechanic character in the 1997 ensemble film—which featured Sean Penn, Nick Nolte, and Jennifer Lopez—Thornton found Cash's enthusiasm remarkable and his direct phone call even more so. The actor attributed Cash's appreciation for the film to the musician's taste for boundary-pushing and unconventional material.

Thornton's account suggests the interaction marked the beginning of a genuine friendship between the two artists, particularly given their shared appreciation for creative risk-taking. Thornton, who split his career between acting and music, maintained this connection with Cash over the following years, despite experiencing ongoing nervousness about their relationship. The friendship persisted until Cash's death in 2003, with the actor never entirely overcoming his sense of awe at having been chosen as a friend by the music legend.