If unpleasant or obsessional, past memories can hurt — but nostalgia is good for you. The benefits of this internal psychological state are touted in various academic studies exploring the art and practice of what could be deemed as pleasant reminiscing.

According to experts, personal memories from long ago of family and friends can link us together in shared comforts of tradition, and also lend a gratifying sense of continuity in our lives.

Nostalgia can take on many different forms. Watching an old black-and-white movie can trigger a cultural nostalgia for a lost period in time. Often that longing can predate one’s own date of birth: fondness for a time only your parents may have known and talked about.

The mental journey back through time adds a fourth dimension to the present. If mindfulness is the focal point of the Eternal Now, nostalgia forms a special continuum to the timeless past, expanding our concept of the self. The future may be vague, inchoate and unpredictable; but the past represents a finished whole that cannot be harmed or tampered with.

Documented reasons why nostalgia (when used intelligently) can be good for us:

It allows us to cast off the stresses of modern life by traveling back to a period of our own choosing. It’s like escaping into the confines of a good book or a darkened theater, but in this case the story is real and (if chosen wisely) has been assured a happy ending.

Especially for the elderly, frequently isolated from loved ones and familiar surroundings, recapturing the past often results in maintaining a positive outlook and leads to purposeful activities, such as telling stories and sharing wisdom from a bygone time.

According to Dena Kemmet, “an additional function of nostalgia may be its motivating potential. Nostalgia may boost optimism, spark inspiration, and foster creativity.”

According to Dr. Clay Routledge, Social Psychologist and Associate Professor of Psychology at North Dakota State University,nostalgia “increases positive mood, self-esteem, feelings of social connectedness, optimism about the future, and perceptions of meaning in life. Furthermore, nostalgia motivates people to focus on cultivating meaningful relationships and pursue important life goals. In addition, as people get older, nostalgia makes them feel youthful and energetic. Nostalgia also reduces existential fears about death.”

The emotion of nostalgia can be evoked from a familiar scent, an old photograph, or a cherished song. Often it occurs during periods of sadness or transition, but it can appear anytime — affecting the young as well as old. Even children as young as eight-years-old can experience the wistfulness of times past.

How nostalgic are you? The research of Krystine Batcho has led New Scientist to create a quiz on the subject, to determine ones degree of wistful thinking. A high score indicates a person more attuned to life and more adaptable to lifes vicissitudes.

The healthy use of nostalgia is not about retreating into the past. On the contrary, exploring the treasures of our “mental” time capsules can propel us toward the future, with a restored sense of enthusiasm and hope. The regular practice of this discipline has been found to be correlated with increased resilience and self-confidence.

For some, nostalgia can come to resemble a spiritual meditation. Indeed, the past is more venerated in places where the future is more fleeting — where constant change is often expected and demanded. The “cushion” against future shock rests on the pillow of slow self-reflection. Such a spirit of languid repose opposes the current epoch, a time when the present is rooted in gross speed and frequent turmoil.

The judicious use of nostalgia offers each one of us who feels stranded in the present an anchor to the past.