In To Kill A Mockingbird, Atticus is a single father who is determined to instill a sense of fairness and the value of human dignity in his children. He has taken on the Tom Robinson case and must defend an innocent man even though he knows that the outcome will not be favorable because the people of Maycomb County are hypocritical and their "blind spots" (chapter 16) will effectively cost a man his life. However, Atticus refuses to judge them, maintaining that it is necessary to "climb into his skin and walk around in it” (chapter 3) in order to understand someone.
The quote referred to in the question occurs when Atticus consoles Miss Rachel (Dill's aunt) and tells her that "they all go through it" (chapter 6); it comes after the children have been caught sneaking around Mr. Radley's garden, trying to look inside the mysterious house which both intrigues and terrifies them. They know they shouldn't have but as Dill will be leaving Maycomb as the summer holiday is over, they saw an opportunity not to be missed. Atticus's reaction confirms his attitude and his demeanor. He may be a "satisfactory" (ch 1) father according to Scout but he has foresight and knows that his children will learn from many experiences as long as they are part of a nurturing and honest environment. Atticus knows that this kind of behavior is a part of growing up; it is essential to the children's development that they push the boundaries, although they must also learn from the consequences of their actions. Atticus wants to help Miss Rachel understand that the children's behavior is not as bad as she may think and that it will ultimately build character. Atticus is revealed as a rational thinker who does not overreact, who understands children, and who is a caring person.