We must exercise ourselves in the things which bring happiness, since, if that be present, we have everything, and, if that be absent, all our actions are directed toward attaining it.

We are happy when we are growing.

It's easy to be heavy; hard to be light.

If you want to feel safe, healthy, and hopeful, try to act as if you did feel that way. "Fake it 'till you feel it." maybe start with health -- try to walk energetically, speak energetically, do physical things.

When we don't get any treats, we feel depleted, resentful, and angry, and we feel justified in self-indulgence. We start to crave comfort - and grab that comfort wherever we can, even if it means breaking good habits.

It was time to expect more of myself. Yet as I thought about happiness, I kept running up against paradoxes. I wanted to change myself but accept myself. I wanted to take myself less seriously -- and also more seriously. I wanted to use my time well, but I also wanted to wander, to play, to read at whim. I wanted to think about myself so I could forget myself. I was always on the edge of agitation; I wanted to let go of envy and anxiety about the future, yet keep my energy and ambition.

One reason that challenge brings happiness is that it allows you to expand your self - definition. You become larger. Suddenly you can do yoga or make homemade beer or speak a decent amount of Spanish. Research shows that the more elements make up your identity, the less threatening it is when any one element is threatened.