No matter how powerful your brain is, it's not powerful enough to remember everything that has ever happened. By the time you are 16 years old, you have experienced around 8,409,600 minutes. Not only is it impractical to remember all of them, there is no value in it. Why would you need to remember every meal you ever had, or what time you woke up every day? What we do remember are those memories that have meaning. Memories with emotional content, and memories with lessons that it's important for us to remember.
There are two key types of memory that are relevant to this course.
The first is autobiographical memory. This type of memory is just about the when and where and who. If I asked you to remember your first primary school, you would access this type of memory. Forgetting these moments is not critical to survival. You will most likely have forgotten many autobiographical events. Most memory enhancing programmes are focussed on this type of memory, because it's harder to remember.
You would also probably ping another type of memory when I asked about primary school- the episodic memory. These memories are 4 dimensional. They have meaning as well as technicalities of when, where and who. They are moments that have important emotional conent. These memories are critical for survival, particularly if the emotion was negative.
This 'pinging' process is how the brain decides what it needs to act on, and what it can let slide when it is scanning for invisible tigers. The simplest way to think of it is like a spider web. A spider builds the web in such a way as individual paths can be removed or blocked, and it's still possible to traverse. When a fly lands anywhere on the web it sends a vibration or 'ping' to the spider, which then goes and fetches it's prey.
The spider in this metaphor is the equivalent of a stored memory. The web is your subconscious, scanning constantly. The fly is a trigger. It's something that happens in the present, that connects back to a memory.
All through life we are creating episodic memories. However, as you will see in the next module, there is a catch! During childhood, these 'memories with meaning' are stored in easily accessible connected webs. When something happens in your present, your brain quickly matches to important memories and immediately acts to disengage your ability to think.