For Amir, storytelling is his passion, something he likes to do in his free time. He wants to be a writer and more importantly, he wants to write fiction - he wants to tell make-believe stories.
Hassan, on the other hand, is entertained by the stories. The stories he hears represent a world with which he has minimal access. He cannot read, nor can he write. He depends upon Amir to tell him the stories, just like he has to depend upon Amir for everything in live.