I'm not saying I walk around with a smile on my face, thinking that will make the world right. Or, that if I just look on the bright side, the best will come.
Example. Two guys tasked to do the same job, a truly horrid job, pick one there are many. Person A goes with the attitude that it needs done no matter what, so digs in and get it done. Person B bitches and moans and complains the whole time. Hating his shitty circumstances life has handed him. Who do you believe gets done faster and does a better job? Hence, a positive outcome.