Amor fati — “love of fate”, was coined by Nietzsche.
“My formula for greatness in a human being is amor fati: that one wants nothing to be different, not forward, not backward, not in all eternity. Not merely bear what is necessary […] but love it.”
It’s hard to convey just how radically optimistic this attitude is.
Nietzsche is referring to the actions we take and the whole web events that our very being is woven into. He writes:
“If we affirm one single moment, we thus affirm not only ourselves but all existence. For nothing is self-sufficient, neither in us ourselves nor in things; and if our soul has trembled with happiness and sounded like a harp string just once, all eternity was needed to produce this one event — and in this single moment of affirmation all eternity was called good.”
Nothing is regrettable.