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You can also say that it's a natural behavior of a human. To be greed, because on the early stages of our ancestor we use to have a system of survival of the fittest and by that there's we get our behavior of we should be not losing because means weak for others.
well, greed is a part of every human being but that doesn't mean that every human being is greedy.
you can actually use that greed and turn it into ambition and become even more successful you just have to add some brain power to it so you make better decisions.