Because his body was soft although his shell was hard, and it was perfectly clear to him what of him was shell and what of him was clam. The shell is dead, it protects me. But it is not me. I am a soft belly body and muscular foot. I move. And I enjoy. But these humans are always moving through life to protect themselves, so have become unclear who is me and who is the armor that protects me. They want to go into a group of other humans and be guaranteed that they will be cared for — by money, by personality, by fame. Foolish humans — their rigor is their tomb. They have become All Shell.