Paul splits the share of potato cakes that his mother gave him with the Russian POW's. Despite potato cakes being his favorite, he knows that the Russian's are still people. They all have lives and wouldn't even be fighting the war had somebody not signed a piece of paper.
Paul and Albert go to the hospital together, but Paul ends up going home early, and they get separated. Despite all of their efforts to stay together, they couldn't do anything about how fast their wounds healed. Paul, in a way, loses another friend.
Kat dies. After Paul carried him the entire way back from the front, in the end, Kat ended up getting a head wound and bled to death. As Paul's best friend and mentor, it really shook him up and he had nobody left with him.
Swatridge, Colin, and Erich Maria Remarque. All Quiet on the Western Front. Macmillan, 1987.
Paul dies. After losing all of his friends, experiencing the "glories" of war, and seeing that there isn't even any hope left at home, he really had nothing left.