Happiness through yoga?

I had tried yoga in my twenties and not felt like I was getting anything out of it. I rediscovered it this year and have begun using a yoga app on my computer quite regularly. Usually when I'm doing yoga I feel calmness rising, tension draining, muscles stretching, that sort of thing. Sometimes I don't really feel anything and just finish the routine because I don't like leaving things unfinished. Today, though, when I did yoga I began to smile part way through the routine. I felt myself settling into the poses. I even anticipated some of the moves before the little voice directed me where to move. It was forty-five minutes of a mostly quiet mind and moments of unexplained happiness.