If you feel like time is flying by as you get older, you're not alone. Here's how to savor the moment.

• As we get older, things such as vacations seem to go by faster.
• Adults tend to have more routines and fewer new experiences, making time feel like it flies by.

When I was 13, summer felt like an eternity. Two of my closest friends had divorced parents. So they would spend most of the summer visiting their dads — one lived in a different city and the other was halfway around the world. I felt like I didn't see them for years.

Now that I'm almost three times that age, it's strange to think how those weeks felt like they were going by at a glacial pace. With each passing year, summer comes to an end, and I start sounding like a TV anchor who's surprised that it's September already.

If you're like me, you may be wondering why it feels like time is going faster as you get older. Neuroscientists explained to Insider the science behind time perception and what we could do to slow things down and keep our brains active and engaged.

Childhood experiences seemed to last longer

Thinking back on your childhood, you might recall getting your ears pierced, trying a sip of beer, riding a roller coaster, or going on your first airplane trip without your parents. Even if you can't remember precise dates or details, these formative years are full of novel experiences.

Brain plasticity is the organ's ability to adapt as needed.

"The brain's high plasticity during childhood means it's rapidly forming new neural connections and storing detailed memories," Hayley Nelson, who holds a Ph.D. in psychological and brain sciences and is a psychology professor and the founder of the Academy of Cognitive and Behavioral Neuroscience, told Insider. "In these rapid-learning periods, the brain encodes more information, making time feel elongated."

Another reason that childhood experiences feel longer is the relative nature of time. As you get older, "each successive year represents a significantly smaller percentage of your lifetime," Todd Handy, who holds a Ph.D. in psychology and is a cognitive neuroscientist and professor of psychology at the University of British Columbia, told Insider. "When you're 5, a year is a fifth of your life, and when you're 60, a year is a 60th of your life."

At 13, I felt like two months dragged out because I was waiting to reunite with my friends. Strong emotions such as anxiety, fear, and dread can make time feel longer, Nelson said.

Just think of how slow time feels when it's the last hour of your workday before a long weekend or when you're sitting in the dentist's chair waiting for the numbing cream to take effect. Time can feel slow in moments when we want it to go faster.

You experience time differently from how you remember it

Deep inside the brain is a structure called the hippocampus, which is responsible for learning and storing memories. When you experience something significant, like failing your driver's test or traveling with your partner for the first time, there tends to be greater activity in the hippocampus, leading to richer memories.

"Later, when you recall these memories, they appear longer and more detailed," Nelson said. "So although an event might feel short while it's occurring, it could feel longer when you remember it."

In addition to how you perceive time, it's worth considering where you're "mentally spending your time," Handy said. You can spend it focused on the here and now, as in the concept of mindfulness. Or you might be engaged in mind wandering, where you're thinking about the past or anticipating what's going to happen.

"It's very natural for our brains to be able to anticipate the future and recall the past, and it's not a bad thing to mind wander," Handy said. Though if you're feeling detached or distracted when you should be enjoying yourself, trying to be more present can benefit your mental health.

Why it feels like time goes by faster with age

While time may feel relative in some ways, it's a finite resource. We have only a certain amount of time, and this becomes increasingly apparent as we age.

"When you're younger, it's really easy to not think about time because you have so much more of your life left to live," Handy said. "As we get older, we realize we have less and less of it, and I think that also can lend a sense of urgency, which makes it feel like it's going faster."

The aging process also leads to physiological changes in areas of the brain responsible for thinking and making decisions. These neural pathways can degrade and affect brain activity in older adults, which might change our perception of time, Nelson said.

"Additionally, adults often have more routines and fewer new experiences, making time feel like it's flying by," she added. Because social media gives us ready access to memories through photos and anniversaries, we also tend to experience nostalgia.

"If we're fortunate, we have a lot of good memories to draw on from the past," Handy said. "At the same time, those can feel deeply bittersweet, especially with respect to kids growing up, losing parents, and missed opportunities."

You can learn to 'slow' down and remember more

There's no magic elixir for slowing down time. Fortunately, there are things you can do to keep your brain active and improve memory retention.

You can start by getting enough sleep, being physically active, and eating a nutritious diet. Practicing mindfulness can also help increase awareness of yourself and your surroundings.

"Activities like puzzles can boost brain functions related to decision-making and problem-solving, helping preserve a consistent perception of time," Nelson said. When you're learning or experiencing something new, your brain is prompted to create brain cells and connections, which can improve memory retention.

Of the countless memories we form throughout life, "we're more inclined to remember novel experiences," Handy said. And because we have better recall for things such as traveling abroad or trying a new cuisine, we may feel like we've done more after having these experiences.

On the other hand, there's value in not putting pressure on yourself to make new memories, especially if your life doesn't match up with your friends' and peers'. "The more accepting we are of our experiences in terms of time passing, the better off we're going to be," Handy added.