Atef is saying life is the sum of your choices, your memories, the realization that love is not going to heal every wound of your soul, and that you will have to keep moving --I notice he didn't say, "moving forward--despite pain. That part I would agree with. Where I would disagree is when he adds, "That's all life is." I think there is more.
Life is also knowing that even if people you love can't "save you" -- you still have to work through your own challenges and heal yourself if you can -- still, there is great solace in loving and being loved. Life is also being able to experience beauty, from nature, from art, music, poetry, and in books -- a broader companionship of souls across time. Life is finding something worth fighting for -- fighting by enduring, fighting by creating, fighting by investing your caring and attention to help others. In short, finding new meaning and purpose when your old one proves to be mistaken or worse. Life is an opportunity for endless new learning. And sometimes life is for stopping to just be grateful for what you can enjoy in your experience.
This was a great question because it forced me to realize what I think Atef's problem was -- not merely his guilt, but his failure to find some other cause to throw himself into, or some other way to fight for the justice that inspired him in his youth, some way that wasn't violent. He had a job, but he didn't have a sense of purpose, beyond survival. Even more than feeling rootless and torn from one's own life, I realize through Atef how profound the suffering is when the grief and loss and survivor's guilt can prevent someone from finding a new purpose in life.