Final answer:
The Mariner in 'The Rime of the Ancient Mariner' realizes he has become a better person when he blesses the water snakes out of genuine affection, marking a shift from his previous thoughtless actions.
Step-by-step explanation:
In the poem The Rime of the Ancient Mariner by Samuel Taylor Coleridge, the Mariner comes to know that he has become a better person through his deep sense of guilt and subsequent realization of love and respect for all of God's creatures. This transformative moment occurs after he blesses the water snakes in a moment of pure, unintended affection, marking a shift from his previous act of thoughtlessly killing the albatross. The sudden ability to pray again, the shedding of the albatross from his neck, and the relief that follows are symbolic of his redemption and internal change towards becoming a better person.