I think the song is about a boy whose mother passed away.
"Don't turn your back on me. Conceal and protect me."
She musn't leave, but protect him
-"When I am an old man, and live by the sea, will all your thoughts fly to me..."
He wants her to contact him, when he is old and grey
-"As much as I want you, I can't hold on to you."
He can't go with her,
"When will you return to your old home again?"
but still wants her to return home.
-"Will all your love bring me home..."
He wants to be unified with her in a time
I think the song is about a boy whose mother passed away.
Etcetera... :)