Remember how long summer vacation felt when you were a child? Those weeks stretched on and on. Now a whole year can slip by between one birthday and the next, and you wonder where it went. So is it just your imagination, or does time really speed up as we age?
The short answer is that it's a real effect, at least in how we feel it. Psychologists have found that our sense of time passing tends to speed up as we get older, and people increasingly underestimate how long a stretch of time has lasted. The exact reasons are still being debated. Leading ideas include changes in the aging brain, simple proportions, and the fact that adults have fewer brand-new experiences than children.
The Brain Changes With Age
One possible factor is biology. As we grow older, our brains change in many ways, including lower levels of dopamine, a chemical messenger in the brain. Researchers think changes like these may help explain why time seems to move faster later in life, though the details aren't settled.
The Fraction-of-Your-Life Idea
Another explanation is all about proportion. To an 11-year-old, one day is about 1/4,000 of their whole life so far. To a 55-year-old, it's about 1/20,000. By this reasoning, a year might feel about five times faster to the 55-year-old than to the child.
This model has a funny consequence. If it were exactly right, the stretch from age 5 to 10 would feel as long as from 10 to 20, from 20 to 40, and from 40 to 80. Another researcher, Lemlich, proposed a gentler version in which time speeds up more slowly. Under his model, a 55-year-old would feel time passing about two and a quarter times faster than an 11-year-old.
Everything Is New When You're Young
The most common explanation is about novelty. For young children, nearly every experience is new: the first day of school, the first bike ride, the first snowfall they remember. Kids have to pay close attention to the present because they're constantly building their understanding of the world.
For adults, a lot of life is routine. The commute, the chores, and the weekly schedule repeat. Those familiar days tend to blur together in memory, which may make a year look shorter when we look back on it.
Memory research fits this picture. People tend to recall an unusually large number of memories from roughly ages 10 to 30, a pattern called the reminiscence bump. Events from those years, like graduations, weddings, and the birth of a child, are often new and distinct, which makes them more memorable.
When Time Slows Down
Our sense of time can also stretch. Research suggests that time seems to slow down during dangerous or intense moments, like a car accident or a skydive. People who are very frightened tend to experience this stretching even more, possibly thanks to adrenaline. Scientists suspect this slowing may have helped our ancestors react quickly when danger struck.
So if the years seem to be flying by, you're in good company. One idea worth trying, since new experiences seem to stick in memory, is to fill your calendar with a few firsts: a new trail, a new recipe, a trip somewhere you've never been. You may find the year feels a little fuller when you look back on it.
