Seppo: No, you didn't miss something. I was just saying that Joe talks about "one big loop" when the movie cuts to a shot of Sid boarding a train by himself and looking angry. Everywhere else in the movie, those cut-aways were only used when the timeline had changed, to show that either young Joe or old Joe suddenly had a new memory because of something that had changed in his own timeline. I mistakenly thought the movie was throwing one more last-minute twist into the mix, suggesting that it was Joe's on memory, Cid grew up to be Joe, and his mother getting shot was the incident that caused him to turn to a life of crime.

Instead, the "one big loop" was simply that Old Joe's shooting Sara was the incident that caused Cid to become the Rainmaker, which is what caused Old Joe to come back and shoot Sara in the first place. And the cut-away was Joe imagining Cid getting on the train, not remembering it.