Extremely loud

I'm really interested in how the main character develops and changes throughout the course of the book.  His actions in the beginning of the book made him seem rather insecure and immature.  He always talked about giving himself a bruise.  Perhaps this was for attention from his mother.  His mother is obviously moving on past the death of her husband and the boy doesn't seem to understand why.  At the same time he seemed to be rather knowledgeable about so much for a kid his age.  He was taking French lessons.  I find that pretty impressive.  He starts on this journey to find the lock to his dads key.  Something like the task he gave himself takes a lot of critical thinking skills and the ability to use logic and reason effectively.  He certainly has smarts and he is very unique.  I just am interested in seeing how the boy changes or if he changes.