This spinoff series is doing a very good job establishing and fleshing out its characters. Iain Armitage, in the title role, is a superb piece of casting, as is Zoe Perry as Sheldon’s mom. And last week, Annie Potts, as Sheldon’s grandmother Meemaw, proved another instant prized addition to this clever sitcom. And tonight, young Sheldon has a life-changing experience, one that we know will affect him greatly in the years to come: visiting his first comic-book store.