I’ll start with one: Never believe that financial management can make you rich.
Financial management ALONE can’t make you rich but do not downplay the impact it can make to your life. If you are poor and you are trying to save money, you should be good at managing your finances. But saving money wouldn’t be enough for you to be rich. After saving your money, what are you going to do with it? Just spend it? Then you didn’t really become rich, no?
Save your money then think of ways how to double said money. Then it’s a cycle that once you start earning you should again manage your finances well.