Passers-by

I was, for some people, a ghost. I went through their lives and then, I disappeared without a trace. They'll never know if I really existed or if I was just a mirage, a trick of their imagination. I've had this tendency to disappear since I was a little girl.
I disappeared from their lives in one of those unpredictable floods that affect us from time to time, none of them ever knew my whereabouts. I'm sure I was nothing but a chimera to them, today I'm not even that.
Sometimes I remember these people, always wrapped in mists built in my own daydreams. What's the use of going back in time when life unfolds fully in front of us at all times?
I am a grain of sand, lost in a non-existent past and in a future that is beyond manufacturing. Passers-by of a made-up life. The memory of some of these people causes me a poignant pain and most of the time I can't even guess the reason. At the end of the day, I wonder who among us is real, is it me or is it them?