We move through life every day, passing hundreds of faces, never realizing even by our presence we affected them, however slight. The though of the sheer masses of beings that you affect just with a passing glance, a casual bit of eye contact, a smile. All of it ties together. Who is to say that smile you give a pretty girl one day isn't the smile that keeps her going the next day when she can't smile; or the nod you give a guy in passing keeps him going through a rough patch by pure association that one person acknowledged him. The affect we have on strangers is a ripple through time we can never see, but when you think on it you can feel it, however slight.