When you are optimistic you are looking for things to work out so you are more likely to see the solutions and opportunities.
You are the only you who has ever been or ever will be - there's a reason for that. You are here to create your world, be the example.
It's not about what happens out there, it's about how you process it. What kind of mood will you choose- gratitude, joy, contentment, frustration, fear, depression - the choice is yours.