The fact is always obvious much too late, but the most singular difference between happiness and joy is that happiness is a solid and joy a liquid.
I think that this quote rocks! Happiness breaks when something falls on it, but joy fits in whatever container you put it in. There is a distinction between joy and happiness I have usually thought of it as happiness being a sort of worldly emotion that comes from some worldly satisfaction - not worldly in a bad way, but in a mortal human earthly way and joy as being something God given that doesn't necessarily make us happy but gives us hope and inner peace . Just some thoughts... Tim