Happy because we sing

I once heard a quote that said "We do not sing because we are happy, we are happy because we sing". This kinda bashes the whole "I'm not in the mood" or "I don't feel like it" defence. I love this because it really puts me in my place when I get on a mood or am feeling down because it says so simply that it's my choice. I have actually tried this. Try singing when you are sad and see how long you stay sad. Of course, in my case if I start singing people are me may start feeling sad. I know now that I can't wait for something to make me happy, I make me happy.