Don't demand that things happen as you wish, but wish that they happen as they do happen, and you will go on well. (Epictetus, Enchirdion 8)
Fate leads the willing and drags along the reluctant. (Seneca, Letters to Lucilius)
My formula for what is great in mankind is amor fati: not to wish for anything other than that which is; whether behind, ahead, or for all eternity. Not just to put up with the inevitable – much less to hide it from oneself, for all idealism is lying to oneself in the face of the necessary – but to love it. (Nietzsche, Ecce Homo, 10)
When the philosophers talk about Amor Fati, "Love your fate", they mean the bad parts. There's no difficulty in loving your fate when you've just won the lottery. Still, it's always been relatively easy for me to grasp why we should accept our fate. It's going to happen, so why fight the unavoidable. It has been far harder to really understand, however, why we should "love" it. It seems Stoic enough if we can just "grin and bear it", right?
Well, no. It's not enough. I suppose it's better than whining about how the world is out to get us, but ideally, life is a lot better once we learn to truly love what the universe weaves into our thread.
Fate, in the form of the challenges it incessantly spawns, is what makes us strong. A universe in which we do not need to overcome challenge, where we do not actively seek it, is one where we grow weak and our lives are bland and ordinary. Our daily struggles are what gives us backbone. Every time we get rained on, or fired, or insulted, or robbed, we get a chance to respond with virtue. And, if we do, we gain resilience, fortitude, and wisdom.
The manner in which we respond to our fate becomes the foundation of our character. If anything determines who we become, it is this interaction. And to be great, to be someone worthy of our own respect, we need a great adversary against which to spar and test ourselves.
And so we learn to actually love our fate, not merely to bear it. We love it because it makes us better. We love it because, without it, who would we be?