One doesn't actually need optimism and positivity to actually have 'luck' or even a brighter view of life.
And pessimism and negativity doesn't always translate to caution nor worry towards uncertainty, nor stops one from recklessness despite the thoughts of 'worst' of aspects and outcomes. Pessimism is just another force to regulate, a bitter or sour kind sure; a fuel to incline caution and, well, defences; but not always.
... Seriously.
Optimism and positivity is the same way. Another form fuel, another compass direction or inclination towards what might some forms of recklessness would likely do to disregard uncertain thoughts of negative outcomes; again, not always. Optimism is just another raw potential force to regulate, that only tastes way sweeter.
But everyone has their preferences. I do not like sour or hard-bitter, and I don't like sickening sweet. I don't do spicy, though it'll be rare. I like salty better, or a good blend of sweet and sour. Except I suck at cooking and following recipes of vocabulary, especially suck at representing them. Yeah, abstract concepts, 'luck', and heck 'forces' -- flavors, recipes and cooking.
It sounds nonsensical. Yes, I'm hungry.