1. Optimists believe that they have the control
Optimist believe that they shape the future. They don't see any reason tomorrow won't be better than now, so conditions and the past have no meaning for them.
But pessimists don't think that they have any control of their lives. If they knew they had control then they wouldn't be pessimists.
2. Optimists look forward
Yesterday is just an experience for optimists. There is nothing better than now, and tomorrow also looks good.
Pessimists don't usually look forward. Actually, they do but what they see is an unpleasant future, which is based on their bad experiences.
3. Optimists have self-confidence
Optimists believe they can overcome anything. But pessimists don't believe any such thing; they just think they are the victim of life.
4. While optimists think that it's possible, pessimists see the problems
Optimists: "What should I do next? I have many choices."
Pessimists: "What should I do next? I have many problems."
5. Optimists have a better life
Of course it offers a better life.