Quality of Light
I was walking down the block to check my mail, and I noticed the light. It was just before night, just before twilight actually, and the ambiance of the sky mixed with the streetlights. It illuminated the trees, giving a new depth to the reality of the street I was walking on.
And it occurred to me that this light would have been entirely different - if it were just the light itself. But this light was moving - constantly changing, and I could feel that by the time I got back to my house, twilight would have fully come. With every step, the light changed.
It's change that makes life special, because real life moves.