I'm afraid if I'd been one of Atticus's children, I would have been bragging about the incident with the mad dog when I returned to school. It would not have been the mature thing to do, but it would have coincided with Scout's own view.
"Looks like he'd be proud of it," I said.
But Miss Maudie explained that
"People in their right minds never take pride in their talents."
Jem took Miss Maudie's advice to heart, recognizing that Atticus took no pride in his secret--that he had been the "deadest shot in Maycomb County" during his youth. Jem was able to convince Scout to keep her mouth shut:
"Don't say anything about it, Scout...
"I reckon if he'd wanted us to know... he'da told us."
Jem also discovered he shared another trait with his father:
"Atticus is a gentleman, just like me."