Optimism means expecting the best, but confidence means knowing how you will handle the worst. Never make a move if you are merely optimistic.
Optimism can be a speculator’s enemy. It feels good and is dangerous for that reason. It produces a clouding of judgment. It can lead you into a venture with no exits. Even when there is an exit, optimism can persuade you not to use it.
You should never make a move if you are merely optimistic. Before committing your money to a venture, ask how you will save yourself if things go wrong. Once you have that worked out, you’ve got something better than optimism. You’ve got confidence.
Growing up (which takes a lifetime) is like finding out what kind of canoe you’re in – and learning how to row it safely and effectively – and learning to accept yours is not the best in the race.
The genetic factor in IQ is well established, which doesn’t (and shouldn’t) stop anyone from attempting to improve their knowledge and skill at reasoning. That said, people with no facility at math shouldn’t aspire to be physicists, and good-looking, loquacious, charming people shouldn’t sit all day behind a computer.
There is evidence that this analysis pertains to optimism/pessimism. Some investors may find they do very well in exuberant bull markets but crash when things go bad; others miss out on “irrational” bull runs, but cautiously avoid crashes. How would society look if everyone had the same rosy disposition, and philosophy that everything bad is temporary and will ultimately and triumphantly reverse by dint of inherent human goodness, the American way, and our G-dly chosen-ness amongst a universe of 10^100^100 habitable planets?
Pessimism (skepticism, risk-aversion, worry, etc) has its place. Some fraction of Jews living in pre-Nazi Europe fled at a time when others deemed flight too fearful and overwrought, with well known results. The survival/perpetuation of fear and pessimism in the population is evidence that it has value. And the difficulty buying when the world is on fire, and holding when money is free illustrates why the rich are in the minority, most heroes are dead, and Gini ratios naturally go up until acted on by the hands of governments or G-ds.