Would it be a smart to take all my money and bet on a hot IPO? Probably not. Too many eggs, too few baskets. I'll likely lose it all and look like a fool. What if the stock skyrockets 300%? Now all of a sudden I'm a genius and people are asking me for advice. If things don't work out - bad decision, if they do - great decision. But it was the same decision! Judging the quality of a decision based on the outcome is known as outcome bias . When making a decision we can only predict the likelihood of possible outcomes . The outcome itself is always unknowable so we can't judge a decision based on it. A good decision is one that is most likely to achieve a desired outcome. No guarantees, bad outcomes can still happen. No matter how much analysis you do, there will always be a degree of luck/risk. To improve your health, exercise is a good idea. You could also seriously hurt yourself - a risk you can manage with proper training but a risk nonetheless. This doesn't