Answer:
I occur twice in eternity. And I'm always within sight.
What has roots that nobody sees, and is taller than trees. Up, up it goes, and yet it never grows.
What can you keep after giving it to someone?
I always run but never walk, I sometimes sing but cannot talk, No head on which a hat to place, You always look me in the face.
What comes down but never back goes up?
I'm the source of all emotion but I'm caged in a white prison.