It's only over time that the memory begins to sort itself out regarding the past. When confronted with the present,,it's much more difficult to remember what you had for lunch the day before,,let alone what time you received a phone-call. Unless these things are immediately written down as they occur,,then vital information is lost forever in a fog of guesswork.
"Original" police logs/documents will have been written as to the crime scene. Though a selective memory came into play when these originals were not adhered to and another set were presented during the trial,,with an edited version of events.
Hence this is why Jeremy has had the time to sit and think about past events,times,,and what he did that particular day. His mind now at this stage will be very much focussed on reverting to the past,,it is obvious,,as sadly,he's had no future to think about,,so therefore lots of things would become clearer to him.