In this issue, we see the repercussions if Jon Osterman hadn't become Dr. Manhattan. Along the way we also see the possible choices Jon could have made with and the world-changing consequences each choice brings. 
 An infinite neural network. This is how Dr. Manhattan perceives events across time. 
 Until now he still doesn't know why the "other" him did not become him. He must have messed up the timeline. This point tells us that Dr. Manhattan, though having godlike powers, is not omniscient. He doesn't have an explanation to all things.