Optimism is the tendency to expect good things to happen and to believe that situations will work out well. An optimist looks at challenges and sees opportunities, at setbacks and sees lessons, at cloudy skies and knows the sun is still shining somewhere above.

When you study hard for a test, believing your effort will pay off, that's optimism. When your science experiment fails but you're already thinking about what to try differently next time, that's optimism. When your team is losing at halftime but you still believe you can win, that's optimism in action.

Optimism isn't about ignoring problems or pretending everything is perfect. An optimistic student knows the math homework is difficult but believes they can figure it out with enough work. An optimistic inventor expects failures along the way but trusts that persistence will eventually lead to success. Thomas Edison failed thousands of times before inventing a practical lightbulb, but his optimism kept him going.

The opposite is pessimism, expecting things to go wrong. While pessimists see obstacles as reasons to quit, optimists see them as problems to solve. Studies show that optimistic people tend to be healthier, more successful, and happier, partly because they keep trying when others give up.