Some time back I was reading a story when half way through the story the facts changed. It’s one thing for a viewpoint to change. Two people might not agree on exactly what happened. The narrative should stay consistent.
I remember one story where it took a couple of days to go from point A to point B later it took several weeks. I’ve seen climate changes and even name changes within a story.
It can be hard keeping track of everything. I’ve worried about that myself. I may introduce a Character then we may not see him/her again for several chapters. How will I keep it all straight?
I’ve created my own fantasy world things to not happen here on Earth. I have several ideas I am working on that all take place in the same world. In order to keep track of things I need maps. First a world map. Next drill down to the continents, then to countries cities and in some cases specific buildings. My world started out when I was a Dungeon Master playing Advanced Dungeons and Dragons. These detailed maps allowed me to keep track of where everyone was, describe the terrain, etc. These same maps allows me to provide detail to my story. If we go into a pub what is the atmosphere, the lay out. Today there is a heath in the middle of the room with a deer roasting over the fire. The bartender cuts a slap off to serve the party members. Weeks later we are in the same city they remember how good the service and food was so return to the same pub only this time a fight breaks out. Does someone get knocked into the heath?
I use excel spread sheets to keep track of things. Each of my characters are entered in with their name maybe a nickname, a description, personality, speech, and so forth. It is important to make your characters as real as possible that includes habits both good and bad. Zentar the oldest son of an Elven Lord feels that because of his birthright he is better than everyone else. He goes on to take advantage of others claiming who and what he wants. When his greatest desire is denied him he goes off in a rage. His brother Candurn being the younger son does not hold himself in such high esteem. Instead He works hard learning to serve his family and his people. When the time comes for their father to select his successor because of his humility it is the younger Candurn whom is selected.
These spread sheets also contain governments, affiliations, guilds, etc. Not everyone who has pledged support of the king is true in their actions. Who can the king really trust? Little facts like these can add a lot to a story. Facts, stories, legions, histories are all things you should record. The king may not trust an adviser because of things that happened in the past. Yet that untrusted adviser may become the king’s best ally.