I actually prefer my fantasy series to be unfinished. For me, a solid majority of the enjoyment is figuring out events and more from clues and foreshadowing.
There are so many things that I picked up on the third read through that I simply would have been told in a later book if they were all available.
"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyse a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects."