Ultimately? The main character is tormenting himself. He knows that the only thing the raven is going to say to him is "nevermore", yet he keeps asking it questions anyway. Each time it's like he's getting kicked in the gut, but he doesn't stop. Poe was never afraid to express how he felt about things when he wrote his poetry, so it doesn't come as a surprise that by the end of the poem the speaker concludes that he's never going to be happy again. I think we've all felt that way at least during one part of our lives before, haven't we?