If you are optimistic for others you ancourage them to do stuf. Doing some stuff that may not work is 100000% better than watching Netflix/TV. Especially in current nihilistic social climate.
Pessimist and optimist are both right (not my quote)
Example: Pessimist: I will not get this job -> So I will not even apply -> 0% chance of getting a job -> 100% correct Optimist: I will get this job -> I apply and prepare -> 20% chance of getting this job -> 20% correct But who cares if you are correct. What matters is taking a chance. This comes way more useful if you are optimistic every day. So you apply for a job whenever there is a chance. And if you apply for 10 jobs from initial 20% you get 89% chance to get a good job.