Answer:
In Jack London's "The Law of Life," Koskoosh vividly recalls a time when he was young and strong and had to kill a bull with his bare hands. This memory contributes to the story's central themes of the natural cycle of life and death, and the harshness of the wilderness. The memory shows how Koskoosh was once a strong and capable man, but now, in his old age, he is weak and helpless. The memory also highlights the brutal nature of survival in the wilderness, where one must kill to survive. The memory is a reminder of the inevitability of death, and how one's strength and vitality can fade with time.