Friedrich Nietzsche said, "My formula for human greatness is amor fati: that one wants nothing to be different, not in the future, not in the past, not for all eternity. Not only to endure what is necessary, still less to conceal it--all idealism is falseness in the face of necessity."
When I first heard this, it didn't make a lot of sense beyond the superficial. Rev. William, currently studying Stoicism, has a challenge coin with Amor Fati inscribed on it that he carries in his pocket from time to time. The notion of accepting my "fate," fate being "whatever life happens to throw at you," is a concept with which I am familiar. But, I think Nietzsche is saying much more than that.
Human greatness is the ability to not only accept our fate but to live beyond the longing for things to be different, no matter how much hindsight we may gain. Any change in our past will ultimately change where we are currently, and desiring a future other than what is in front of us will lead us to miss where we are headed. It is the ability to completely embrace the now of our lives, complete with the mistakes of our past actions and the potential consequences (or new mistakes!) ahead of us.
Idealism is not a basis for a life path. There are no ideal journeys. "Ideal" is only the beginning, the outline, of our planning. The rest is made up of finding ways to mitigate the risk of the more likely and less ideal circumstances we WILL encounter. For us to truly attain greatness, we must not only endure what is necessary, we must THRIVE in the face of it. Necessity drives us to kindle the Needfire that is only called upon to answer the greatest of our questions. It is in the face of necessity that we put the bow drill to work to create the spark of inspiration that we may build a blazing fire of becoming in the face of adversity.
Amor Fati. Desire nothing to be different in your past. Desire nothing to be other than it is right now. Desire nothing to be different moving forward. The world around us will continue to evolve, to ebb and to flow, carrying us with it through the vicissitudes of life. Focus on what is necessary and the rest will tend to itself.