The power of positive thinking only works for those people who are already happy.

Many people, including clients, think that "If I'd just try harder at being happy, I'd be happy." It doesn't work that way. Telling someone to cheer up has never helped them to feel cheery. Telling persons to stop putting themselves down has never lessened their feeling bad about themselves. In the Peanuts cartoon, Lucy's therapy is meant to be a joke. In real life, that kind of therapy is no laughing matter.