As wild as some of the events of the poem are, Howl is really about "the morning after." The first two lines of the poem are "I saw," not "I see." Our speaker has woken up from a month-long bender, and he wants to tell us everything he saw, even though he's bleary-eyed and blood-shot, undernourished, exhausted. He's a witness. He has to share these stories with someone and, fortunately, that someone is us.
The speaker seems to talk a mile-a-minute, so his words don't come out in the proper order. When he says things like, "who poverty and tatters and hollow-eyed and high," we want to say, "Whoa there, buddy, that's not proper English – back the train up for a second." But he's like, "No time to stop – gotta tell everything, gotta just spit it out." When you look closely at the syntax of Howl, the order of its words and phrases, you realize that it emulates the way someone on drugs or suffering from mental illness might speak. Just like your English teacher says, "Show, don't tell." The speaker of Howl is a living, breathing embodiment of the mental state he describes.
The speaker is also a smart guy and very well read. He has been to college and learned about William Blake, the philosopher Plotinus, and the Dadaist movement in France. He loves books, but he doesn't bury himself in them. He likes to be out in the world, traveling around and experiencing the best and worst that society has to offer. His best friends are homeless men and drug addicts and people who sleep on the subway. He's also very loyal toward his friends, which is why he can't forget about his good buddy Carl Solomon, who is stuck out there in Rockland psychiatric hospital.
He's the kind of guy you might meet at 4am in an all-night diner, who shouts his opinions at you over his fifth refill of coffee. He has strong views and wants you to have them, too, even if you disagree with him. He puts heart over head, to the max.
Although his life may seem like one adventure after another, he's really a sad and melancholy dude. He says his friends have been "destroyed," and he's struggling to figure out how it happened. In the middle of the poem he gets angry and starts shouting about Moloch. "It's all Moloch's fault! If I see that Moloch, I'm going to punch him in the nose!" Then he remembers about his friend Carl and gets sad and reflective again. He has a dark sense of humor, which keeps him going when times get rough.