(Click the character infographic to download.)
House: Gryffindor, 3rd Year
Poor Harry never manages to have a quiet year at Hogwarts, does he? Aside from doing homework and playing sports and dealing with friendship drama, Harry also has to square off with some sort of evil nemesis every year. And we don't just mean school bullies (Malfoy), horrible teachers (Snape), or crazy guardians (the Dursleys). No, we mean über-evil villains like Voldemort. And in this book, the Dementors.
In Book 3, our boy-wizard hero confronts death and fear head-on in ways that start to prepare him for everything that's going to come later. Overall, this novel is a transitional story for Harry. He's starting to leave childhood behind and begin his journey to adulthood. And the journey isn't an easy one for him. So it makes sense that Harry has to deal with a lot of emotional upheaval, as well as other types of drama this year. And by drama, we mean a crazed murderer is after him. Hey, we never said he was a normal kid.
It's a truth universally acknowledged that teenagers often don't get along that well with their parents. So what does this mean for Harry, practically the most famous orphan character ever, when he hits his teen years? Well, Harry has to deal with his parents' memory, sacrifice, and legacy in some really intense ways over the course of his first year in puberty land.
The Dementors actually kick this off for Harry – whenever he's around these creepy would-be reapers, Harry hears the final moments of his parents' lives, before Voldemort murders them. This is some really dark and disturbing subject matter for a children's book to deal with, much less a thirteen-year-old kid. And for all the ways he's extraordinary (his Quidditch talent, his status as the "boy who lived," his knack for getting into trouble of the life-threatening variety), Harry is also just a regular kid. So, dealing with his parents' deaths, up close and personal, is extremely painful and difficult for him.
Then Harry's thoughts wandered back to his mother and father [...]
He felt drained and strangely empty, even though he was so full of chocolate. Terrible though it was to hear his parents' last moments replayed inside his head, these were the only times Harry had hear their voices since he was a very small child. But he'd never be able to produce a proper Patronus if he half wanted to hear his parents again [...]. (12.3.76)
His connection to his parents, and to his father in particular, is represented in Harry's Patronus. But Harry doesn't just spend the entire novel living in the past. He has plenty of stuff to deal with in the present too.
Harry experiences a steadily growing awareness of the wizarding world and its history. There's a definite tension between real-world events and school antics in Book 3. As Harry starts maturing emotionally over the course of the novel, the action gradually shifts away from things like concern over visiting Hogsmeade. Harry starts focusing on more important things in life, like friendship and family and conquering his fears, rather than Firebolts and Butterbeers and Hogsmeade candy.
The outside world increasingly intrudes upon the fairly enclosed world of Hogwarts, probably best represented by Black's break-in attempts at the school. Moments of extreme immaturity (his fight with Hermione, sneaking out, concern over fitting in as opposed to worrying about an escaped convict) are offset by moments of extreme maturity, like asking his father's friends to spare Pettigrew.
This isn't to say that Harry just grew up overnight here. He's still a kid, albeit a very savvy one. Harry is on his hero's journey in this novel and on his journey to adulthood. The two aren't anywhere near finished yet, but by the end of this book we begin to see new sides to Harry, like his capacity for mercy, his ability to overcome his anger, his ability to reach out to a friend.