Regardless of age, you're unlikely to have a flawless memory. People who can remember very long lists of numbers or recall the minutiae of their daily lives — right down to what they ate for lunch every day last year—are exceedingly rare. And frankly, such a memory can be a burden rather than a blessing. Memory, it seems, is inherently flawed—and in more ways than you might think.
Daniel Schacter, a professor of psychology at Harvard University, described the most common ways that normal memory fails us in his book The Seven Sins of Memory. Some of these memory flaws become more pronounced with age, but unless they are extreme and persistent, they are not considered indicators of Alzheimer's or other memory-impairing illnesses. They are simply the way that our brains work. The following is a brief summary of two of Schacter's seven memory "sins."
This is the tendency to forget facts or events over time. You are most likely to forget information soon after you learn it. However, memory has a use-it-or lose-it quality: memories that are called up and used frequently are less likely to be forgotten. Although transience might seem like a sign of memory weakness, brain scientists regard it as beneficial because it clears the brain of unused memories, making way for newer, more useful ones. In this sense, transience is akin to cleaning the junk out of your closets or clearing the temporary files from your computer's hard drive.
Although everyone experiences transience of memory, it is extreme and debilitating in people with certain kinds of brain damage. For instance, people with amnesia that is caused by injury to the hippocampus have normal short-term memory, but they are unable to form new long-term memories. They forget information soon after they learn it. This is not the type of transience that normally affects people's memories.
This type of forgetting occurs when you don't pay close enough attention to the information you want to remember. You forget where you just put your pen because you weren't focusing on where you placed it. You were thinking of something else (or, perhaps, nothing in particular), so your brain didn't encode the information securely. Absentmindedness also involves forgetting to do something at a prescribed time, like taking your medicine or keeping an appointment.
One way to avoid this problem is to identify things that can serve as cues to remind you to do something. For example, if the doctor tells you to take your medicine at bedtime, you might use another regular bedtime activity as a reminder cue for medicine-taking. In this situation, you could link it to rinsing after toothbrushing, and use the same water glass to sip water to take your pills. Similarly, if you need to take your vitamins at breakfast, you could make a habit of putting the bottle beside your coffee cup at your place at the table so it provides a cue when you sit down to eat.
To learn more about the differences between normal memory loss and symptoms of something more serious, purchase the Special Health Report, Improving Memory, from Harvard Medical School.