River seldom leaves her diary unattended, citing ‘spoilers’ as the reason she won’t let him read it. She doesn’t want him knowing details of events she’s already lived through that he has yet to experience. On one hand he knows it’s a sensible precaution, but on the other… Well, curiosity is one of his major personality traits, so from the moment he first set eyes on that bulging book he’s been longing to get his hands on it.
When he finally does it’s almost insulting; River’s written the whole thing in code! Does she really think he can’t decrypt it?