Is it better to be realistic or optimistic? A realistic outlook improves chances to negotiate the environment successfully, whereas an optimistic outlook places priority on feeling good. But are realistic and optimistic outlooks necessarily in conflict? The author suggests that the fuzzy nature of accuracy typically places only loose boundaries on what it means to be realistic. As a result, there are many forms of optimism that do not, in principle, yield unrealistic assessments. Nevertheless, there remain numerous "optimistic biases" that do involve self-deception, or convincing oneself of desired beliefs without appropriate reality checks. The author describes several ways that realistic and unrealistic optimism can be differentiated and explores the impact of this distinction for current views of optimism. This critique reveals how positive psychology may benefit from a focus on personal meaning and knowledge as they relate to making the most of life.