In reply to Chuck.

And I read a discussion about the movie that suggests there may have been one other time they cut away to something that wasn't really a memory. When Old Joe murders the first kid, he has a flash of him and his wife in the future having a baby. I'd thought it was clearly him having a new memory now that the timeline had been changed.

But somebody made the suggestion that because that kid wasn't the Rainmaker, it couldn't have done anything to change Joe's timeline that significantly. (I'd been thinking that any change to the past could change the future, but really, getting into the butterfly effect would have made the movie unnecessarily complicated). So the cut-away was actually another case of Joe imagining what would happen. He was trying to convince himself that it was worth it because he was fixing everything, and he'd end up with a better future this time, and even that bringing a new child into the world would make up for the one he'd just killed.