But That Was Yesterday lyrics

I thought this love of ours
Was here to stay
Your heart was true when love was new
But that was yesterday

Our love was warmer than a summer day
And ev'ry kiss told of our bliss
But that was yesterday

Yesterday's memories
Bring today's sorrows
Now that you're gone from me
We share no tomorrows

I still remember
Dear, the plans we made
You always said "Some day we'd wed,"
But that was yesterday

Submitted by Guest

What do you think is the meaning of But That Was Yesterday by Neil Diamond?