"A large part of any relationship takes place in our minds, so it's natural for it to continue much as before after the other person's death. It is easy to forget that your sister is dead when you reach for the phone to call her, since your relationship was based so much on memory and imagined conversations even when she was alive. In addition, our agent-detection device sometimes confirms the sensation that the dead are still with us. The wind brushes our cheek, a spectral shape somehow looks familiar and our agent-detection goes into overdrive. Dreams, too, have a way of confirming belief in the afterlife, with dead relatives appearing in dreams as if from beyond the grave, seeming very much alive...We have a basic psychological capacity that allows anyone to reason about unexpected natural events, to see deeper meaning where there is none. It's natural; it's how our minds work."