Decision making is a multi-faceted subject. It goes beyond just deciding yes or no. As the resources below will show you, there are a number of ways to make decisions optimally.
Why do people do what they do? Behavioral economics seeks to combine economic theory and human behavior to answer why.
Daniel Kahneman is a giant in the field. Start with his work:
First principles thinking is the act of boiling a process down to the fundamental parts that you know are true and building up from there.
I love reading Naval Ravikant and listening to his podcast appearances. How to Get Rich (without getting lucky)
Specific knowledge is knowledge that you cannot be trained for. If society can train you, it can train someone else, and replace you. Specific knowledge is found by pursuing your genuine curiosity and passion rather than whatever is hot right now.
Conspiracy believers are the ultimate motivated skeptics. Their curse is that they apply this selective scrutiny not to the left or right, but to the mainstream. They tell themselves that they’re the ones who see the lies, and the rest of us are sheep. But believing that everybody’s lying is just another kind of gullibility.
Conspiracy theorists seem to be people who are uncomfortable with the unknown. Explanations for unexplainable things, no matter how outlandish, are better than the alternative. The alternative is to accept that things sometimes just happen. There isn't always an explanation.