Winston Churchill once said, "A pessimist sees the difficulty in every opportunity; an optimist sees the opportunity in every difficulty." Research shows that, on average, human beings are hardwired to be more optimistic than not. It's an admirable quality, one that can positively affect a person’s mental and physical health. Optimism can also help reduce a person’s stress and increase longevity. Some optimists consistently ascribe benevolent motives to others and interpret situations in the best possible light; others simply disassociate their internal mood from external circumstances, no matter how sticky. Being optimistic is not necessarily always the "best" strategy, though. Research shows that tempering a sunny disposition with a small dose of realism, or even pessimism, might be the best way to build resilience and achieve one's goals.