Does your experience say that this approach works well for you? It is pretty and a lovely sentiment, but for most of us it's ineffective. on those days when one's cat dies or one has PMS. or even on the average day.
I hesitate to call it "the kind of happiness", because I think joy and happiness are two separate things, but yes, joy doesn't depend one what happens. God gives you joy; therefore, joy is something nothing and no one can steal from you.