I like to imagine everyone leaves some kind of vapour trail throughout their lives. Like if you open the exposure on a camera for a long time and aim it at a single person, walking across the shot, their movements would be caught, and they would seem one long blur of motion? Well imagine birth as the opening of the shutter, and death as it's closing. And all that we do in between as being our vapour trail. Except it's not just all that we physically do, it's all we emotionally do too, to ourselves and each other. I like to imagine that they're all coloured, and the lives we lead affect the brightness of our trails.
Wouldn't the city be a more magical place if we walked it's streets leaving a bright and vibrant trail where ever we went, and if we wanted to, we could trace a persons steps to see how they've lived, how they've loved, the mistakes they've made, and hopefully how they made up for them?