Nope, not joy, just plain cheerfulness. I'm surprised because a simple choice to be cheerful really does make a difference. It doesn't necessarily come from a deep place of joy or anything else profound, but choosing to put a smile on my face, not be grumpy at the grocery store and just make the most of the good stuff certainly makes my day (and everyone else's) go a whole lot better. You don't even have to feel particularly cheerful to start out. Like scales, it's something you can practice, and the more you do it, the easier it gets and the better you sound. Like the old proverb goes, A merry heart doeth good like a medicine: but a broken spirit drieth the bones. Cheerfulness is just a nicer way to live.