In general, dreams offer an escape from real life. Sure, there's the one about the algebra test you haven't studied for (that one's the worst), but dreams are also where you get to flap your arms and fly or make out with your favorite celebrity. However, David's dreams are often as depressing and disturbing as his real life, so when he ends the book with a dream that he's a shut-in, you fear that he's become just as screwed-up as the adults who raised him.
Like most of David's dreams, this one gets really heartbreaking really fast: he can't leave the house, so he experiences the world via a small remote-control car. One day, however, he sneezes while controlling the car from behind a window, and accidentally drives it into a fountain.
As he contemplates going outside to get it, he hears the sound of someone sweeping, and he looks over the garden wall for the first time. It's his mom clearing a path up the steps to the asylum where his grandmother died, making room for him in the family madhouse. But when she motions for him to follow, Small gives us his decision in white text on a final, all-black page: "I didn't."
It may not exactly be a happy ending, but given that Stitches is a pretty dark read right up to the last page, the final sentence feels like a triumph—like light in darkness. We've waited through the whole book for David to get free of his family, and now he's on his way. We'll call that a victory.