It seems strange, but as I'm wrapping up this third novel, I'm consistently having to widen my own memory net.
Whenever any author writes their novel, unless they're intimately aware of everything they're talking about, they inevitably have to dig in and research. For The Bindings of Fate, I had to study up on castle terminology (and I had to brush up on it some more for The Enemy Within), and I needed to research weaponry somewhat. In As Darkness Falls, I did some looking at dragon history and dragonology.
Now, as I said, I'm beginning to get to the hind end of my third book. I'm probably over 1,000 pages into my universe now, not including supplemental work, like the encyclopedia that I've been working on, or the games. At this point, there's so much going on, that I often retread my steps in the narrative one way or another. I think it's a good habit to take your readers back to something familiar, even if you have to explain it in a different light.
One of the reasons that I started writing up the encyclopedia was to have an easier way to keep myself in check. I'm fully aware of all the major details - people's appearances, their fighting styles and weapons, etc. - but with so much going on, it's nice to be able to look back at something without scrounging too much, and finding out, "alright, yeah, that's exactly how I thought it was." The last thing you want to do is forget your own material. While I haven't done that yet - as far as I can tell - I'd like to make sure I don't in the future either.
This is an especially daunting task because of the aforementioned supplemental pieces. With all the sideways and historical lore, there are plenty of things that I could incorrectly reference, if I'm not careful. For the game we're currently working on, the main character is a creature that's only mentioned twice in the second book. I was intentionally vague in their descriptions, but even the details that were given had to be taken into consideration. That had to be worked into the concept art for the main character of the game. Rhianna had me running around the house on all fours like a gorilla the other day for reference, just to make sure she understood the description right.
That is the nature of this foray into my mind though. If you're going to do something of this magnitude, that doesn't mean you take shortcuts to end the journey quicker. No matter what you're working on, it's better to take the time to perform your task, whether it's research, or narrative, to the best of your ability. You can't take back your integrity once it's out in the open, so it's best to make sure you polish it as much as you are able.