I feel a sentimental longing when I recall the day I attended a The Cure concert with my friends, the mornings I drew on the condensation of the school bus windows, and the evenings I played board games and watched Disney movies with my brothers.
Clearly, this wistful longing for the past is quintessential nostalgia.
It turns out that I'm far from unusual. Some 79 percent of people report that they feel nostalgic on a weekly basis, when recalling personally important events.
Common examples include birthdays, Christmas holidays and weddings – occasions when we are surrounded by family and friends.
But how do we become nostalgic about events and what psychological function does nostalgia play? Our new research, published in Cognition and Emotion, sheds some light on the issue.
Nostalgia was actually considered to be a disorder for centuries – a sad and anxious longing for something that is gone or far away. But today we know that it can have important psychological benefits.
While it can sometimes be triggered by negative emotions such as loneliness, it has been shown to improve mood and make life feel meaningful.
It provides feelings of being loved, protected and connected with others and can trigger inspiration and optimism about the future by helping us remember good things about ourselves and others.
Creating nostalgic memories
But how can we create nostalgic memories in order to reap these benefits? My colleagues and I speculated that savouring life experiences may help turn them into nostalgic memories.
Perhaps it is the case that when people are in the midst of a meaningful experience, they often find themselves making extra effort to capture every moment of it.
In three new studies, we investigated whether savouring an experience is implicated in the creation of nostalgic memories. We began by examining if people are more nostalgic for events that they savoured.
We first instructed 266 participants to spend a few minutes thinking and writing about a positive event from their past.
Immediately after this, they were asked to answer questions assessing how much they had savoured the event when it took place, and how nostalgic they currently felt about it.
We found that the more participants had savoured an event, the more nostalgic they felt about it. This finding does provide initial evidence that savouring is important for the creation of nostalgic memories.
We extended the experiment in a second study, by focusing on savouring and nostalgia for a general life period rather than a specific event. We specifically looked at the life period of attending university.
In this study, we also examined whether nostalgia for a previously savoured experience is associated with the psychological benefit of optimism.
We approached 122 university alumni during a reunion event and assessed how much they had savoured their time while they were university students, and how nostalgic they currently felt for that period in their life. We also assessed how optimistic they were about their future.
We found that the more participants had savoured their time at university, the more nostalgia they felt for that period in their life. Additionally, participants who felt more nostalgic for the savoured life period reported greater optimism about their future.
In all, this study supplied further evidence that savouring contributes to the formation of nostalgic memories, and also evidenced nostalgia's downstream implication on optimism.
One limitation of the first two studies is that participants' reports of how much they had savoured a life experience were retrospective.
In other words, participants' reports of how much they had savoured a particular life experience during the life experience came after the experience was over.
To circumvent this issue in the final study, we measured savouring of a currently ongoing experience that was about to end.
Then, we measured nostalgia for that experience at a later point in time, after the experience was finished.
Specifically, we approached 66 university students during the day of their graduation ceremony and assessed how much they were savouring their last year at university.
Then, four to nine months later, we contacted participants and assessed how nostalgic they felt for university and also how optimistic they felt about their future.
We found that the more participants savoured the last year of university, the more nostalgic they felt for university life several months later. And again, nostalgia for the savoured experience was associated with greater optimism.
These studies suggest that a deliberate effort to capture and appreciate a present experience provides the foundation for nostalgic memories. So if you want to create more nostalgic memories for the future, do make sure you really cherish special occasions.
It could give you joy for years to come – with nostalgia often triggered by smell, music or weather. Thinking about that live performance of The Cure certainly always puts a smile on my face. 
Marios Biskas, PhD candidate of Psychology, University of Southampton.
This article is republished from The Conversation under a Creative Commons license. Read the original article.