Sukkot is z'man simchatenu -- the season of our rejoicing.  But the megilla associated with it is Kohelet (Ecclesiastes), which is a downer and somewhat depressing.  Why?  Sources say it is to provide a counterweight to unbridled rejoicing.  Perhaps so, but the problem is that the Torah says: Vesamachta bechagecha, vehaita ach sameach -- You will rejoice in your holiday, you will ONLY rejoice. [Deuteronomy 16:14-15] The word "only" seems to exclude "counterweights".  So what is the resolution? (Note: Most Sephardim don't read Kohelet on Sukkot.)