https://twitter.com/doesdatmaksense
April 29, 2025
Forgetting is one of the most fundamental parts of being human. We can understand something deeply, feel it click into place, and still find it slipping away after a few weeks or months. It feels strange, even unfair, but it is not an accident. Forgetting is not a failure of memory. It is how the brain was built to survive - adaptive, selective, and constantly evolving.
Memory was never meant to be a static archive. It is a living system, constantly rewriting itself to prioritize what matters most now.
At the biological level, memory begins when neurons strengthen their connections through a process called synaptic plasticity. These links form the physical trace of a memory, but they are not permanent. If a memory is not reactivated through recall, reflection, or use, the brain lets the connections decay over time. Synaptic decay is not a flaw. It is the brain’s way of keeping itself efficient, clearing space for new learning and preventing overload. "Unused for six months? Probably not vital anymore."
If the right cues are missing or obscured, the brain struggles to find the stored memory, even if it is technically still intact. Think of it like having a book somewhere on a giant bookshelf, but forgetting which section you placed it in. Accessing memory depends on cues - sights, sounds, smells, emotions that guide the brain toward the right pathway. This is why memories sometimes come flooding back unexpectedly when we encounter a familiar environment, a smell, or a related idea. Accessing memory depends on cues - sights, sounds, smells, emotions that guide the brain toward the right pathway.
(This is why active recall and spaced repetition work so well, they keep the retrieval pathways alive.)
Initial understanding of a concept is just the first stage of memory formation. To become long-term, memories must go through a process called consolidation, where they are stabilized, linked to existing knowledge, reinforced through repetition and emotional significance, and strengthened during periods of rest, especially sleep. Without this ongoing reinforcement, even deep understanding remains fragile and can fade over time.
The human memory system is deeply tied to survival. It prioritizes information that is emotionally charged or directly relevant to personal safety, well-being, or long-term goals.
Memories associated with strong emotions, personal relevance, or high stakes are much more likely to be consolidated and preserved. If something was emotionally meaningful (like "this changed how I see the world"), it's much more resistant to forgetting.
When we are young, our brains are undergoing rapid neurogenesis, forming new neurons and strengthening synaptic plasticity at a high rate. Attention is sharper, and energy is often directed toward intense learning. Students often experience faster encoding and stronger short-term recall because the brain is optimized for absorbing vast amounts of new information. As we grow older, even within a few years of starting work, we begin to notice changes. Focus is spreaded across multiple responsibilities. Stress, repetitive routines, and reduced novelty blunt the mind’s natural plasticity. Sleep patterns, critical for strengthening memory, often suffer. Without realizing it, the brain shifts from "rapid learning mode" toward "knowledge maintenance mode," and the effortless recall we once took for granted becomes harder to summon.
While forgetting is part of how the brain stays adaptable, there are ways to work with its design instead of against it.