Time is the continuous flow of occurrences, starting from what was, existing now, and leading into what will be. It is the irreversible progression of events, measured and perceived differently by each observer. We experience time through the cyclical nature of the day and night, the seasons, and the aging process. Time's passage shapes the world around us, eroding mountains, creating canyons, and influencing the evolution of life. It governs the rise and fall of civilizations, the birth and death of stars, and the very fabric of the universe. Though invisible and intangible, time is a fundamental dimension, a constant companion that shapes our past, defines our present, and determines our future. It is the relentless river, carrying everything and everyone forward, never stopping, never turning back. Understanding time is a pursuit that has captivated philosophers, scientists, and artists for centuries, and it continues to be a profound mystery, a force both powerful and subtle, that shapes our very existence.

The human brain, a complex and dynamic organ, doesn't experience time in a linear, clock-like fashion. Instead, our perception of time is intricately linked to the creation and recall of memories. The more intensely we experience an event and the more details we encode in our memory, the more "time-rich" that event becomes. This is because the brain uses memories as markers for the passing of time. When we reflect on a period and can recall a wealth of distinct memories–vivid experiences, significant conversations, novel challenges, or emotionally charged moments–that period *feels* longer. Each memory acts as a data point, expanding our internal timeline. Conversely, when events are less memorable, perhaps routine or monotonous, fewer details are stored, and the period seems to compress. Time seems to "fly by" when we lack distinct memories to anchor us to the past. Therefore, the subjective experience of time's pace is not constant; it's malleable, shaped by the density and richness of our accumulated memories. This principle has implications for everything from our childhood recollections to our later-life reflections, affecting how we perceive and value the moments that make up our lives.