Success is, quite simply, achieving your goals. The only reason why there is any discussion, is because of the confusion over what your goals should be, which is an entirely different topic. Similarly, since your goals will be different than the goals of other people, success will look differently. One person in a $1000 isn’t necessarily more or less successful than the Dad of 5 kids. The only metric worth looking at is whether those were the intended outcomes.
Keys of Success
There are three keys to success: Rationality, Psychology, and Game Theory. Rationality will teach you to think clearly. Psychology will teach you about the forces that govern you and your peers. Game Theory will teach you how to navigate and use those forces to your ends.