Why not rewrite from the start?

Couldn't Brendan Fraser just write his own story where he gets his wife back Paul Bettany goes back to his book and everyone is happy?

Throughout I was thinking maybe you can't write your own story but then the daughter does. I found it enjoyable, good for what it was and if I was a kid I'd probably like a lot but I just don't get why they wait till the end just before it seemed everyone was going to die before writing something?

Maybe I missed something which if I did I'd accept but from what I remember it seemed obvious to do.

Film of 2013
http://www.imdb.com/list/MyXTL3f7TtQ/