My life is like a long journey thru a tunnel.
Each time I see a light, I think it's the light of sunshine, and I'm nearing the end of the tunnel. but it turns out to be another crazed brakeman on a push-car, who whizzes past, and smacks me upside the head as he goes past. When I come to, I can never tell which direction I was headed in originally, and have to guess.
For all I know, I've been walking back and forth in the same 20 meters at the center of the tunnel, all my life, never making any real progress.