If you want to lead an optimistic life, learn to argue with yourself. The secret of optimism is not positive thinking. It's non-negative thinking, according to Martin Seligman in the book Learned Optimism: How to Change Your Mind and Your Life.
The stories we tell ourselves can limit us or enable us. In any given situation, we’re telling ourselves stories about other people, the situation and ourselves. In these stories, we can play the victim or we can be the hero.
When it comes to sleep patterns, some people really are night owls or early birds. According to John Medina in the book, Brain Rules: 12 Principles for Surviving and Thriving at Work, Home, and School , 30 % of the population is an owl or a lark (an early bird in scientific literature.) The rest of us are called hummingbirds where some of us are more owlish and some are more larkish and some are in between.