What is the main cause of memory fading over the years?

The main cause of memory fading over the years is primarily linked to the lack of use. Memory operates on the principle of "use it or lose it." When certain information or skills are not regularly recalled or practiced, the neural connections associated with them can weaken over time, leading to forgetting. This phenomenon is part of the broader understanding of memory consolidation and retrieval; if memories are not reinforced through retrieval or application, they can diminish, leading to difficulties in recalling them later.

While other factors like stress, trauma, and distractions can influence memory performance in specific contexts, they do not primarily account for the gradual decline of memory over long periods. Without regular engagement with information or experiences, the brain may allow those connections to fade, which contributes significantly to memory loss with the passage of time.