There is scientific support for your guess.
Actually some studies suggest, that people with the clinical diagnosis "depression" have a significant more accurate estimation of risks and chances in life.
"Normal" and "healthy" people (for whatever those terms mean) usually underestimate risks, chances of failure or bad outcomes; they overestimate chances of success, good luck etc.
Conclusion: it seems to be important for our mental health that we don't see this world how it really is.
My mother and I have had this general conversation in real life about 500 times. She gets some "great" idea, I tell her it's going to bite her in the butt, she calls me a cynical bastard (which is fair), and lastly, she puts her idea into motion ... and it bites her in the butt. She's told me "I don't care if you're right all the time, I just can't stand your negative attitude!" I guess the secret to happiness is to happily prance your way to poverty one boneheaded decision at a time.
A quicker way to get rich is to be the first person in a Pyramid scheme. (Those people who haven't been bothered by an Amways promoter should ask their mummy to change their nappy before she clicks on to the next strip).