Happiness is Lazy 8s for the fun of it. Solo flying just because I want to fly, need to fly, after another one of those weeks and those days. Where co-workers complimented me on maintaining my cool in very contentious conditions.
Happiness is leaving behind the cares of the world. Or the fact that two students cancelled on me making my revenue generating day a revenue reducing day. I got to fly and that's what matters.
Happiness is doing some darned good normal, short and soft field landings in gusty, crosswind conditions after not flying that type of aircraft for what seems like forever. Doing one of the hardest commercial maneuvers within PTS spec on first try (and 2nd and 3rd and 4th - I was having fun!) the first and only time I've done Lazy 8s after my CFI check ride in December.
Happiness is the joy of flight, of playing in the air, of freedom. That's happiness.