Memories have different lifespans. Some memories last for only a few seconds, others for days or months, or even a lifetime. We usually forget 90% of what we learn in class within 30 days. And the majority of it is forgotten within the first few hours. The lifespan of a memory can be increased by repeating the information in spaced time intervals. In other words, repeat the information many times, but don’t squeeze the repetitions together, space them out in a systematic way. Maybe 3-times on the first day, once more 3 or 4 days later, and again every 6 months to a year.

The events that happen the first time you’re exposed to information play a disproportionally greater role in your ability to accurately retrieve that information at a later date.

Memory retrieval works best if environmental conditions at the time of learning are recreated. That includes mood. For example, if you learned something while you were sad, it’s easier to remember it if you’re sad at the time of retrieval.

The more you focus on the meaning of the information you’re trying to learn the better you’ll process it and remember it. This is best achieved through relevant real-world examples. The greater number of examples the more likely the information will be remembered. The more personal the example, the better.

In an attempt to fill in gaps, the brain infers, guesses, and even uses memories not related to the event. The brain does this in attempt to create organization. The brain is constantly receiving new inputs and needs to store some of them in places already occupied by previous experiences. New knowledge can become intertwined with past memories as if they were encountered together.

Transforming a short-term memory into a long-term memory can take years. During that time, the memory isn’t stable. Forgetting plays a role in our ability to function. It’s a way of prioritizing. Information deemed irrelevant would cause too much cognitive load. There are people who have a special ability to recall everything, but they tend to have difficulty with meaning.