Piers anthony wrote a fantasy series with the idea of it being somewhat educational. It has this thing where the stories take place in different points in history and its like the characters are reincarnated but its not even quite like that. It is that everything that happened in the story has happened to the characters but the time period changes but at any particular point in the stories the characters would remember all the events as taking place in the time period they are currently in. Its hard to describe but I really liked it but I now notice there are five books and I only read the first three.