I am probably in the running for "least optimistic human being alive" in reality. I'm also not at all very mindful, generally, not am I what I could typify as particularly confident.
Thing is, many events are somewhat ambiguous, in the sense of how you should necessarily react to them emotionally. If we follow the line of reasoning though, that meaning if a function of focus, then we can see how focusing on the "negative" will necessarily lead you to a negative interpretation of more events.
Depressive realism is an actual thing. Blissful ignorance is too. The key is finding the right sort of balance between the two.