Terpines continue to mature. THC degrades. You can slow the process by storing in cool, dark places since both heat and light lend to thc degrading. That isn't necessarily a bad thing though. We have yet to scratch the surface of these types of questions. What exactly happens over a cure, especially long cures, doesn't have much information. As the thc degrades, terpines change and the buzz, taste, flavors change as well. In my experience, sometimes for the better, sometimes not.