The mind is a terrifying and fascinating thing.
Wellcome Library, London / Tom Phillips / BuzzFeed
We don't remember everything that we experience.
At The Conversation, Amanda Barnier, a professor of cognitive science at Macquarie University, Australia, writes:
Wellcome Library, London / Tom Phillips / BuzzFeed
In essence, memory can be thought of as a sequence of information-processing stages with three basic tasks:
1. get information in (encoding)
2. save information over time (storage)
3. get information out (retrieval).
Things that we experience go into our sensory memory and stay there for a few seconds. If we pay attention to them, they'll get lodged in our short term memory – which can hold a few chunks of information for about 20 seconds. But if you don't then use or rehearse the information in your short term memory, you'll forget it.
That's why, if a day has no particular significance, or you have no reason to recall it in the near future, you won't necessarily remember the details of where you were or what you did.
If you do rehearse the information in your short term memory – calling a phone number that someone just told you, for example – it can enter your long term memory and you might be able to recall it much later.
Lots of factors can influence how someone remembers something.
"Significant or emotional events typically are better remembered, especially when well rehearsed," Barnier writes. "But even reported memories of significant, well-rehearsed events can vary over time. Such fluctuations may be important or unimportant; it is difficult to tell."
And interviewers can influence how a person remembers an event. According to a Forensic Outreach report: "A witness's memory report will be influenced by the interviewer's questioning style, the content of questions, and the verbal and nonverbal feedback received."
Wellcome Library, London / Tom Phillips / BuzzFeed