- Towards the end of Chapter 1, Dumbledore makes it clear to McGonagall that he does intend to leave Harry with relatives who will probably abuse him just for having magical powers, and she protests. When Hagrid arrives with the baby and hands him to Dumbledore, the Gentle Giant actually whines and cries because of how sad it is and even McGonagall seems close to tears. After putting Harry down on the doorstep, Dumbledore himself also stares at him for a while from the distance before leaving.
- Then in Chapters 2-3, you find out how right those misgivings were. The Dursleys, as much as possible, act as if Harry wasn't there, keep him in the cupboard under the stairs so he takes up as little space as possible, give him only hand-me-downs from Dudley so they can spend as little on him as possible, and ignore/enable Dudley and his friends bullying him not only at home but even at school to the point where he had to run away from them often and once while running he ended up on the school roof. Not to mention, whenever something weird happens, they are quick to punish Harry.
- 11-year-old Harry looking into the Mirror of Erised and seeing his dead family is heartwarming and heartbreaking and somewhat iconic in terms of the series as a whole. Dumbledore's claim that the Mirror shows himself with socks is hard to read after you've read Deathly Hallows and know what he really sees: The same as Harry does, his family alive and well.
- Ron's Heroic Sacrifice during the chess game, though he survives.
- The film's version of the Hut on the Rock. While his relatives sleep, Harry celebrates the coming of his 11th birthday... by drawing an image of his birthday cake out of soot on the floor, making a wish, and blowing out the candles as midnight passes. And considering how his life has been so far, you have to wonder whether this was the first time he's done this. (It does make the cake that Hagrid gives him moments later that much sweeter, though.)
- In the book, he hums "Happy birthday" to himself while the others are asleep, huddled under the thinnest and most hole-ridden blanket his relatives found and threw to him after telling him to find an even spot on the floor, watching Dudley's fluorescent watch to know exactly when midnight will come since (as he remarked earlier when he was locked up in his cupboard) he doesn't have any.
- Ron saying that Hermione doesn't have any friends; given her tearful reaction, it's rather harsh. She is just a good student and, being Muggle-born, likely has to deal with issues from all sorts of other students and not-so-nice teachers, so being mocked about her apparent loneliness could have led her down the same path of another brainy Muggle-born girl with no known friends.
- After Harry is named the new Seeker of Gryffindor's Quidditch team, he's worried that he'll make a fool of himself, since he's never played Quidditch before. Hermione reassures him that he won't because it's "in his blood." She then shows him and Ron a trophy case for the school's past Quidditch teams, which reveals that Harry's father James was a Seeker as well. While this scene starts out as heartwarming, it quickly turns heartbreaking with one simple exchange between Harry and Ron, and it fully sinks in that, until he came to Hogwarts, Harry pretty much knew nothing about who his parents were and what they were like, no thanks to the Dursleys.Ron: Whoa... Harry, you didn't tell me your father was a Seeker, too!
Harry: I... didn't know...
Tear Jerker / Harry Potter and the Philosopher's Stone
WARNING: Spoilers are unmarked.