When I was in junior high and high school, everybody seemed to listen to Drivin N Cryin. Whether the singalong “Straight to Hell” or the riffy “Fly Me Courageous,” the band’s songs were among the staples of our musical diet in 1980s and ’90s Alabama, in part because the constantly touring band from Atlanta played all-ages shows in Montgomery and nearby Auburn pretty regularly. Drivin n Cryin came from that 1980s college-rock scene in Georgia that yielded an eclectic array of bands that include Widespread Panic, REM, and Indigo Girls, who each took their own slant on a mixture of Southern swagger, eager rebellion, working-class intellectualism, and influences that included their parents’ classic country and their old siblings’ punk rock. Though this documentary is not new, “Scarred but Smarter,” named after the band’s first album, takes a look at Drivin N Cryin then and now, and asks the question: why weren’t they more successful than they’ve been?