[FriedrichN]

I'll second the recommendation of fiction (I love the classics) and add a recommendation for reading philosophy and specifically the history of philosophy. Learning how our frame thinking evolved from the time of the Greeks to the middle ages to more modern times has been nothing short of illuminating for me personally. I don't think you need to read the original works or the really academic stuff (you can if you want to) but having a feel of how our thinking got to be is really useful.