Master chief has been known for being very lucky. Maybe that is because he has pre instructions in his brain to make all the right decisions just like born-stellar did to find the didact.
Maybe chief's pre determined goal is to find the librarian?
master chief also always remembers a mother figure from when she was young. This is most likely his actual mother, but who knows. It could be the librarian like chakas saw her at birth.
[Edited on 01.25.2012 5:12 PM PST]