You can't be successful at everything. You can't have it all. So any vision of success has to admit what it's losing out on, where the element of loss is. .. there is going to be an element where we're not succeeding.
And the thing about a successful life is that a lot of the time, our ideas of what it would mean to live successfully are not our own. It's bad enough not getting what you want, but it's even worse to have an idea of what it is you want, and find out, at the end of the journey, that it isn't, in fact, what you wanted all along.
Great speech on definition and philosophy of success