Board Thread:Naruto Discussions/@comment-24807838-20140816203900/@comment-17623-20140818004243

During his academy days his test scores were terribad, he couldn't mold chakra well (not his fault mind you), and he spent more time causing trouble than actually trying in class.

That said, he has incredible drive that will make him succeed when he puts his mind to it. It would be incorrect to say he was completely untalented, but during his youth he didn't have talent in anything because he didn't try.