This sounds like it should be true, but from life experience, I don't really think it is.

It would be rational for things to work that way, but personalities and emotions are not very rational.

There are some people who seem like they have everything in life going for them, and they're still pessimists, their narrative of the world is petty and ugly, or cruel.

Conversely, there are other people who have suffered tragedies that I might consider literally unbearable (i.e. suicide-worthy), and they are still optimists.

I think these are more fundamental personality traits. You can see it in siblings that grow up in essentially identical conditions, but one has a "sunny disposition" and another is anxious and worried.