This is one of those song that you like it the very first time you hear it. i like it now as well, since the first time I ever heard it.
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Sam: you've been waiting much too long now
It looks like she's not coming home
Sam: you've been loyal, true and faithful
All this time with being alone

If I could get that same dedication
I'd give you everything in creation
If she doesn't come back
(If she doesn't come back)

Chorus:
I'll be your substitute
Whenever you want me
Don't you know I'll be your substitute
Whenever you need me

Sam, every day you waited for her
I've been waiting here for you
Sam: all this time I've been lonely
I know what you've been going through

I'll wait until my chances occur
Cause you can't keep relying on her
If she doesn't come back
(If she doesn't come back)

Chorus

Each day by your window you sit and sigh
Hoping to see her face
Oh, you might as well forget about her
And find someone to take her place
(If she doesn't come back)

Chorus

Don't you know I'll be your substitute
Whenever you want me
Don't you know I'll be your substitute
Whenever you need me (repeat 2 times)