Pain is always forcing itself upon me, you... us. Pain is a wretched thing, with venom, fangs, constricting muscles; not at all unlike a serpent.
It lies in wait for you to unexpectedly tread along it's path and then it strikes you and leaves you crippled.
Yes, pain can be a lesson. Often times a good lesson. But how many times has it crept upon unsuspecting prey, coiling itself around a throat until no breath comes from it anymore? Pain is vicious and cold, an adversary that cannot be overcome...