Once in rabbinical school a group of us decided to celebrate Sukkot by going out to Joshua Tree National Park and building a sukkah there and spending the holiday. Everything went well until the Sukkah blew down during the first night of the holiday. Needless to say, that put a kink in our holiday plans.
But it teaches an excellent lesson about the holiday. Sukkot is a time of rejoicing but it is also a reminder that our lives are, if not so much meant to be, than they simply are fragile. Our plans will often go wrong or fail, bad things are bound to happen, things are just going to be unfair. And yet Sukkot teaches us in the face of all this to be happy.
We aren't meant to be happy in a foolish, don't try sort of way - you do build the Sukkah after all, this isn't the holiday of sleeping bags. But we need to be able to laugh, to still be happy, to still love and give thanks, even when the sukkah blows over.