Spike's story is a paraphrasing of a children's parable by Sano Yoko -- Here it is in its entirety: http://goo.gl/h9i4n
There was only one cat who never looked his way.
She was a beautiful white cat.
The cat would go up to her and say: "I've died a million times!"
"Oh." is all the white cat would say.
The cat was a little angry, for you know he liked himself better than anyone else.
The next day and the next, the cat would go up to the white cat and say:
"You'll probably only live once, you know."