Can't remember

I had an idea about something, but now I can't remember.  I was singing old songs, the clue is in that emotion.  I think I was standing out somewhere; the street by your house, the street by mine.  There were white cars ready to take us.  I resisted getting in, but it was there for me; what could I do?   The future's a better place, the driver said.  I waved goodbye to all that way.  I knew I'd miss it; I miss everything.  The past has value, and everything of value is missed, sooner or later.  Way off in the distance, you miss it still, but with perspective.  "Don't look back, don't turn around," the singer guitar player warned.  Or was he pleading?    

I had an idea about something, but it's not any clearer now.