What change Jem and Scouts mind after they thought that Atticus wasn't athletic

One of the things that changes the children's minds about Atticus is when he shoots Tim Johnson, the rabid dog, in the street. Heck Tate was not a good enough shot and asked Atticus to do the job. Atticus is perhaps the best shot in Maycomb. Atticus also takes his glasses off and makes the shot. Scout and Jem are shocked that their father could pull off such an athletic-like feat.