" He also said, "I suppose there are people who are so `lucky' that they are not touched by phantoms and are not troubled by fleeting memory and know not nostalgia and care not for the ache of the past and are spared the feather-hit of the sweet, sweet pain of the lost, and I am sorry for them-for to weep over what is gone is to have had something prove worth the weeping. "

― Isaac Asimov , It's Been a Good Life