Not even sure what is meant with "lifting you off the ground" - does this refer to giving someone sitting on a lawn a hand and pull him up? Or like you lift up a child? Does the parent become the child and the son the parent?
Or does this simply refer to how children grow up, and need to go their own way, become their own person and move away from their parents. In regards to the roles we play, the role "son" totally changes.
Or maybe it's just poetry that is meant to pull you out of the dream world and into the real world?
I think it's the very ambiguity of those words that makes it such a powerfully haunting line, evoking loss, memories, and questions of what (if anything) we can really cling to in the end.