I was always here, I never left.

You thought I was gone? I was always here, I never left.
I am constant in motion but always in place.

I belong to the sea but am found on the land.

I am old as the hills but as ephemeral as this instant in time.
Try to grab me and I am gone. I can hold you but I cannot be held.
I can be felt but I cannot feel.
What am I?

You thought I was gone.
Did it feel like a long time to you?
400 million times I have felt the earth pass round the sun,
I have made volcanic rocks hiss, cool and contract.
I have seen glaciers receding to the North,
Whispering "We will return."
Did it feel like a long time?
I yawn and turn in my bed,
In that time your life has come and gone.

Do not question my constancy.
I was always here, I never left.