"
hear me calling?
'Cause every night, I'm talkin' to the moon
Still tryin' to get to you
[Verse 5]
In hopes you're on the other side
Talking to me too
Or am I a fool?
Who sits alone
Talking to the moon
[Outro]
I know you're somewhere out there,
Somewhere far away...
He is asking "do you really hear me, or am I crazy? " and saying "I can't let you go, and I need you." These sentiments are reflected again in the last lines. It's easier to think of a deceased person as some where else rather than totally gone.