FOUND THE PROBLEM

Optimism and pessimism are not strategies. They are outlooks.

It's purest egocentric sophistry to conclude that your regard of a problem will have any effect on its outcome. The way you feel about something will only affect your interaction with it, and the interactions of those you interact with. Your emotions have as much effect on the physics of the situation as the color of a car has on its wet-weather performance.

However

The way you regard a situation or problem has a definite impact on the way others regard you and if you haven't figured it out yet, lemme tell ya: a negative outlook is about the most divisive thing you can throw into a group dynamic. There's a reason all those African kids you always see are smiling - smiles are non-threatening. Smiles indicate you are open. Smiles are what we do to growling dogs to calm them down.

The only thing you can affect are the dynamics of your interpersonal relationships. Pessimism corrodes them and retards their potential. Optimism is truly inspirational - you will find that a positive outlook and charisma are closely correlated.

So it comes down to this: you and the rest of humanity are careening through a universe of physics, chemistry and probability together. If you do it with a smile on your face, the rest of the human race will try to help you. If you do it with a frown they avoid you. Depression is isolating in many ways - not the least of which it makes people not want to hang out with you. So take it from someone who spent the entirety of his teenaged years on the ragged edge of jumping off a cliff - fake it 'til you make it.

THAT is rationality: recognizing that there aren't many things you can impact, but pessimism impacts them negatively.