How could he fly?

I took it as symbolic. The whole movie was a fantasy, really. His fantasy of how to break free from the constraints of a society that didn't understand him.

I know it was presented as having really happened, especially at the end, but symbolism is really what it's all about. That no one can ever limit what they think a "mentally handicapped" child is capable of. By witnessing him fly, the entire town learned that.

It didn't really matter how he could actually fly.

I think Eric in someways was a Telekinetic, instead of being like Carrie being able to project and move objects around herself... I think Eric's character possessed it being so in himself, and his belief in being able to fly... Allowed him to levitate and fly, when he grabbed Milly's hand at the end and they flew together, he extended that power so she could fly with him..

I always have dreams about flying like that. Except I can't control it and I'm flopping around everywhere. I saw this movie as a kid. I'm sure it had something to do with it..