I think it's primarily because people learn throughout their life. If you spend time with toddlers, you'll notice all of them exhibit antisocial behaviors and have difficulty regulating their emotions. Children whose parents take the time to help them with their emotions and discipline them to teach them socially appropriate behaviors will usually learn how to manage their emotions and behave in socially acceptable ways by the time they become an adult. Children whose parents neglect to teach them about their emotions or fail to adequately discipline them will often have difficulty managing their emotions and exhibit antisocial behaviors. People who were neglected may gradually learn how to behave and manage their emotions through experience although anyone can learn more quickly by reading books about childhood emotional neglect and emotional intelligence.
Everyone makes mistakes since no one is perfect. Unless you've harmed someone, there is usually no need to apologize.
That makes sense. But, there are situations where children were raised properly, but they still exhibit antisocial behaviors as older children.