Hidden Details You May Have Missed in “The Big Bang Theory” – 2By Holly Adler / January 23, 2021 A Teenage Star IMAGE BY: Viacom Before “The Big Bang Theory,” Galecki’s most famous role was the teenage David Healy on “Roseanne.” His costar, Sara Gilbert, also ended up playing a recurring character on “The Big Bang Theory.” Pages: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26