The concept of forever as finite. About promises made and broken.  The chorus has a chordal turn around in it which is an homage to Paul McCartney and “Yesterday”..the whispered “remember” is a reference to “Walking in the Sand”

The sun comes up on another day
Just like they said it would
& life goes on all around me
Acting out the role I play

You said that we’d be together
‘til the end of time
A love to last eternity
You said, “forever & forever you’d be part of me”
Well, forever ended yesterday

Heavy feet drag along the drab grey sidewalk
Carry me blindly to the fray
Every day an empty cup full of heartache
Remembering the time you’d say (I remember)

You said that we’d be together
‘til the end of time
A love to last eternity
You said, “forever & forever you’d be part of me”
Well, forever ended yesterday

I used to be an optimist
Think that nothing could go wrong
Through thick and thin together
We could weather every storm
Now distant waves come crashing down
Our castle built of sand
And all my confidence has faded now
Left me wringing my hands

You said that we’d be together
‘til the end of time
a love to last eternity
you said, forever, & forever you’d be part of me
Well, forever ended yesterday
Forever ended yesterday