When Lily died to protect her son, she gave him a unique protection, made of her love for him. While he has this protection, Voldemort could never touchh him without suffering great pain. We were given something similar. By standing together, we keep the story alive.
Many years ago, in the early days of the Potterheads, I read about the Velveteen Rabbit. It had always been one of my favorite stories, next to Harry Potter. In it, I discovered that you make something real by loving it.
We all loved Harry, his family, and his story. It all became real, yet we never noticed. There were subtle hints, yet we never saw them, only now, with the story as we know over, do we see that it all became real. We loved it into reality. It's an old magic Voldemort would never have known. And we learned it from a rabbit.