Why does jem tell scout to keep it a secret that atticus is the best shot in the county in to kill a mocking bird?

Jem tells Scout to keep it a secret that Atticus is the best shot in the county because Atticus doesn't like to boast about his skills, especially when it involves violence or using a gun. Atticus believes in humility and does not want to glorify his marksmanship abilities, especially to his children.