For using nostalgia in meditation in a practical manner, I see it like this: Richard Rose used to say that guilt is a mixture of fear and nostalgia, fear being we’re afraid of being punished for the act that brought on the guilt, and nostalgia being the longing for the relatively innocent state we were in before the act. Think of it in terms of a lifetime. We may feel guilty about having lived what we come to see as a meaningless life, or an unfulfilled one. The fear manifesting as the fear of being punished for our life asleep, of not being awakened, of wasting our chance. We will die, and not know why we lived, perhaps have to pay karma for our mistakes, and just the plain old fear of death, the unknown. The nostalgia would be from the longing for our innocent state before life affected us, such as the innocent state of a baby. We didn’t have problems or even an identity then, and sense it was better. Especially if we have children or have been around babies, we can pick this up.
Nostalgia is the key to using emotion to find our way back to our original state. If we only use the mind and the imagination in our search, it becomes dry and hollow. The emotional element is brought in by the nostalgic mood; it lends a direction, a practicality, and a motivating factor missing from the head only approach.
– Bob Fergeson