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Optimism from WikiPedia:

Optimism is "an inclination to put the most favorable construction upon actions and events or to anticipate the best possible outcome". It is the philosophical opposite of pessimism. Optimists generally believe that people and events are inherently good, so that most situations work out in the end for the best.

Alternatively, some optimists believe that regardless of the external world or situation, one should choose to feel good about it and make the most of it. This kind of optimism doesn't say anything about the quality of the external world; it's an internal optimism about one's own feelings.[citation needed]

A common conundrum illustrates optimism-versus-pessimism with the question, does one regard a given glass of water, filled to half its capacity, as half full or as half empty? Conventional wisdom expects optimists to reply, "Half full," and pessimists to respond, "Half empty" (assuming that "full" is considered good, and "empty", bad).

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