What are some instances that illustrate that Bruno is young and naïve in Chapter one of John Boyne's The Boy in the Striped Pajamas?

In The Boy in the Striped Pajamas, Bruno's naiveté is demonstrated in his first reaction when he sees his things being packed and he believes that he has done something wrong. Then, he does not realize that they are leaving Berlin, nor the reason for this move. 

In addition to these examples of Bruno's naiveté, he seems to only know that his father wears a "fantastic" uniform. His knowledge of the man and woman who visit...

In The Boy in the Striped Pajamas, Bruno's naiveté is demonstrated in his first reaction when he sees his things being packed and he believes that he has done something wrong. Then, he does not realize that they are leaving Berlin, nor the reason for this move. 

In addition to these examples of Bruno's naiveté, he seems to only know that his father wears a "fantastic" uniform. His knowledge of the man and woman who visit their home--the "Fury" and the pretty blonde woman who waved good-bye to him as he was sent from the room one day--is very limited, as well.

Further, as he speaks with his mother, Bruno suggests that they need to return soon because he has "made plans" for the summer with his three friends, Karl, Daniel, and Martin. Then, he is shocked when his mother tells him that they are making a rather permanent move and he should say good-bye to the three boys, "as if the making of a boy's three best friends for life was an easy thing."