The feeling that each passing year vanishes faster than the last is a nearly universal experience. Psychologists have spent over a century investigating this phenomenon, with the most persistent explanation rooted in the so-called Janet’s Law.
First proposed by philosopher Paul Janet in 1877, the theory suggests that our subjective perception of time is relative to the total length of our lives. For a ten-year-old, one year represents 10% of their existence, making it feel substantial. For a fifty-year-old, that same year accounts for only 2% of their life, leading the brain to process the interval as significantly shorter.
Data from Psychology Today supports this, showing that individuals consistently report a sense of accelerating time as they age. Experiments further reveal that older adults frequently underestimate set intervals of time compared to younger participants, suggesting the phenomenon is measurable in laboratory settings.
The role of routine and biology
Mathematics alone does not tell the full story. As people enter their twenties, life often becomes structured around repetitive routines like work and household duties. Psychologist Robert Ornstein demonstrated that the brain perceives periods with higher densities of new stimuli as lasting longer. In childhood, every experience is novel and rich in detail, whereas the adult brain tends to filter out the familiar, resulting in a compressed sense of time.
Biological factors also play a role. Some theories cited by Psychology Today suggest that children possess faster physiological rhythms, including heart rates and respiratory cycles. These faster internal clocks mean that, subjectively, children experience more events within a standard 24-hour window than adults, whose metabolism and internal processes have slowed.
Neuroscience confirms that the brain relies on internal clocks influenced by attention, motivation, and emotional state. When we are deeply focused or motivated, we perceive time as moving faster. Conversely, states of boredom or high awareness of the clock can make time appear to drag.
Despite the tendency for time to accelerate, the process is not necessarily inevitable. Research indicates that the brain can effectively stretch the perception of time by introducing novelty. Engaging in new activities, traveling, or learning new skills increases the volume of information the brain must process. By breaking routines, individuals can disrupt the sense of rapid acceleration, effectively altering how they experience their daily lives.
