It’s common to sometimes find yourself longing for the past — to think back on your childhood or early adulthood and wistfully recall memories that leave you feeling warm and fuzzy. That’s called nostalgia.

“It’s the positive, wistful, or longing sentiment that one experiences when they are reminded of something from the past,” says Deanna Woodhouse, a licensed marriage and family therapist and director of clinical operations at Los Angeles-based Lightfully Behavioral Health.

Nostalgia could come about by looking at an old photograph, talking with a friend, or smelling a familiar scent.

It’s a question psychologists are particularly interested in. “It can influence people’s well-being,” says David Newman, PhD, an assistant professor in the department of psychology at Loma Linda University in California, who studies nostalgia.

It comes up clinically as well. “Sometimes when a client needs a grounding point, we will discuss things they look back upon fondly and draw upon the nostalgia experience,” Woodhouse says. “Nostalgia can be beneficial when dealing with dark times and reminding clients there was once light.”

Science shows that thinking back on your memories is primarily a positive experience, and that nostalgia, practicing nostalgia, or the act of feeling nostalgic supports people’s ability to find, maintain, and restore meaning in life.

Here are five other benefits linked to nostalgia:

1. It May Promote Sense of Self

Reminiscing about the past can help you feel connected to who you were in the past, who you are in the present, and who you will be in the future.

“If you are fondly recalling memories that align with your values and morals, this can affirm movement toward those ideas,” Woodhouse says. “This would definitely increase the sense of self and motivate confidence.” She adds that oftentimes thinking back on your former self reunites you with your values and what truly matters to you.

2. It Can Serve as a Barometer for Personal Growth

Nostalgia can also show you how far you’ve come. “Change doesn’t happen overnight,” Woodhouse says. “When we can draw upon those positive experiences and reflect upon our own growth, nostalgia can be a good barometer to gauge how we have stayed aligned with our own values (which may change over time, and that’s okay) and our authentic selves.”

She says looking back at the past can help you see where you have evolved and how you’ve grown into who you are in the present.

3. It May Boost Mood

Nostalgia can lead to a positive effect, according to research. If you’re feeling bogged down by negativity, dipping into nostalgic feelings could help alleviate those emotions temporarily.

“This can allow someone who is highly dysregulated to calm themselves down and utilize healthy coping mechanisms,” Woodhouse says. Recalling positive memories can transition emotions from negative to neutral — or even positive, Woodhouse says. After all, it’s common to feel a little boost from thinking back to happy Little League memories or how satisfied you felt eating your grandma’s famous cherry pie as a kid.

It also helps put our emotions into perspective by reminding us that good and bad times are temporary. We can lean into the good while knowing that the bad also does not last forever.

4. It May Help Strengthen Bonds With Friends and Family

Research shows nostalgia is a highly social emotion that connects us to others.

And it works even if you’re complete strangers and connecting over shared experiences from the past, such as millennials relating over ’90s cartoons and dial-up connections, Woodhouse says. “Nostalgia can unify our experiences.”

5. It Could Make You More Optimistic

Nostalgia can increase optimism. This is rooted in the fact that, oftentimes, reminiscing about fond memories brings us back to happy times. “When we remember good times or reexperience love, it can remind us of feeling successful and accomplished,” Woodhouse says.

Optimism is having the ability to think positively of the future, and recalling moments that made you feel courageous, happy, successful, or any other positive emotion gives you an optimistic lens to see the future through, Woodhouse says. “This can help us live each day to the fullest or even help us see the beauty that is in everyday life,” she says.

Most of the time when someone talks about nostalgia, they’re referring to personal nostalgia, or longing for moments they’ve experienced in their own life. As mentioned, this experience is generally positive, but it can bring on sadness, too. Dr. Newman calls it a mixed emotion.

Anticipatory Nostalgia

Anticipatory nostalgia, for instance, which is missing the present while you’re still living it, can result in sadness. Anticipatory nostalgia is defined as the “premature missing of what is still present” and “future loss.”

Reflective or Restorative Nostalgia

Nostalgia can also induce sadness if you’re yearning for the past, and upset that the times you’re thinking of no longer exist. “When you long for a time in your past, it can make you miss that time,” Newman says.

Woodhouse has seen this as well. “When we start to reminisce on the ‘good old days’ and begin to linger in the past, we can ruminate on the ‘what ifs’ and ‘should haves,’ which can lead to depression,” she says.

Whether the experience of nostalgia will be positive or negative can depend on how it’s introduced. One study has found that it is more closely linked with sadness if the nostalgia was unprompted and came up organically during the day. But it’s more positive if you’re specifically asked to reminisce.

Historical or Collective Nostalgia

In addition to personal nostalgia, there’s historical or collective nostalgia, which is a longing for a time in history that you did not personally experience, according to the American Psychological Association.

“For example, you could feel nostalgic for the Renaissance era even though you never lived during that time,” Newman says.

Historical nostalgia can be dangerous, however, if someone in power uses it to push society back toward negative concepts and practices, such as racism or discrimination. Newman adds that there can also be a positive side to historical nostalgia in that it can lead to a greater sense of connectedness. “So there could be some benefits and harmful consequences, too,” he says.

• Nostalgia is the positive and longing sentiment we experience when reflecting upon a past memory or event.

• Nostalgia benefits our well-being by reminding us how far we’ve come as individuals, in turn, boosting our self-esteem and optimism. It also unifies people over shared memories.

• While nostalgia is a mostly positive experience, it can potentially lead to depression if we begin to idealize the past in unhealthy ways.

Additional reporting by Andria Park Huynh.