This phrase is suggesting that success is not having to worry about money, because you have enough to support yourself financially and do not need to worry about it. Instead, success means being so secure that you can focus on other things in life and not have to worry about money. It implies that if you are financially secure, you have time and energy to focus on the important things in life, such as relationships and passions. To be successful then is to be able to worry about everything else in life, except money.