What Friedrich Nietzsche took from Charles Darwin is the idea of radical contingency, and so Nietzsche’s amor fati (love of fate) is an embrace of all of life’s contingencies. Do you have the courage to embrace your existential situation (what Sartre called being-in-itself) right now, as it really is? Or are you pushing the material conditions of your contingent existence away from you, wishing you were elsewhere? Here’s how Nietzsche put it in Ecce Homo (sec. 10):
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, still less conceal it—all idealism is mendaciousness in the face of what is necessary—but love it.
In other words, your contingent existence right now is the raw material for your will, and to spend this moment wishing you were elsewhere—in some other contingent set of circumstances—is to lose this one. So you better be doing what you want with it.
Don’t you love it?