Writing an Epic Fantasy can be great fun, but at times it makes your head hurt. Writing a good plot is one thing, but writing six, or more interwoven plots with multiple lead characters and a large cast of sub characters, all at the same time can be like juggling balls, and there is always more balls to juggle. You end up hopping from one plot to the next to try to keep them in the same time frame and all on track in order to build up to the ending when all of those threads come together in a glorious finale. It can certainly be a challenge.
You think you’re doing fine, and then suddenly you remember some irrelevant detail from three books back that now has become critical for you to tie up and resolve, otherwise you’ll look a right numpty.