I was on a train on a rainy day. The train was slowing down to pull into a station. For some reason, I became intent on watching the raindrops on the window. Two separate drops, pushed by the wind, merged into one for a moment and then divided again - each carrying with it a part of the other. Simply by that momentary touching, neither was what it had been before. And as each one went on to touch other raindrops, it shared not only itself, but what it had gleaned from the other. I saw this metaphor many years ago and it is one of my most vivid memories. I realized then that we never touch people so lightly that we do not leave a trace.
Peggy Tabor Millin in her book, "Mary's Way"