Ex Nihilo and Books

Have you ever noticed that when you open up a piece of literature you are thrust into the middle of a story?  You are introduced to Billy, who is twelve and on his way to school, or to Bilbo Baggins celebrating a birthday at a very old age.  But how could this be?  You are only on page 1.  Why is the author writing in such a way to give the appearance of age?  Why does this really not bother us?  Why does it seem to bother so many when they look at the universe?  What does the universe look like on page 1?  What does a universe look like an instant after ex nihilo?  Could it look like Billy at age twelve?  Is that OK with you?