The Mariner, when he sees a speck on the horizon, bites his own arm and sucks his own blood, in order to moisten his mouth enough to call out. Nothing else seems to exist in the universe. He blesses the water snakes and the Albatross falls from his neck. In honouring one of the lowliest forms of creation, he has restored his connection to nature and placed himself again in relation to the world outside himself. But the experience does not end here.
Further expiation is necessary.
The pilot boy is driven mad and sees the Mariner as the Devil. Like a fever returning to the body, the agony of his experience periodically seizes him and he is compelled to seek out the special listener who is destined to hear his tale. We don't absolutely know, but we know the experience has changed the Wedding Guest's life. Communication is both a blessing and a curse. It is part of our human obligation that we are condemned both to hear out our fellow human beings in their extremity and to recognize in their stories, potential stories of ourselves.