learning and memory

My professor is highly critical of clinical psychology (he's a neuroscientist) and I guess I am as well--this idea of normality is so vague. People who cannot function with whatever brain or emotional imbalance should get diagnosed so they can receive treatment and learn to cope, but I don't know. He said something that made me piece together another part of my personal puzzle. I understand that there is childhood 'amnesia' purely because the brain is still pruning itself and working out the most efficient wiring techniques, so I do understand why languages or skills acquired during childhood would be more successful than those acquired during adulthood. The wiring is there and the connections between the entire brain have been strengthened over time. (it's the whole use it or lose it thing. i believe it's true.) Anyways, he said the entire purpose of memory is to learn and survivability. In a person who has not developed maladaptive thoughts or recalls memories over and over, he or she will remember things that serve a purpose for survival. We are more likely to retain something that is unique to other events in our life so we can retrieve it for future reference.

I was always confused with why my memories were so jumbled. He used this analogy of a card catalog system: when we experience something similar or new to something we already have memories about, this new information is put on that same "card" so details can be mixed up. He said instead of forming a new 'card' of information, if the experience is similar to something you've already 'catalogued' it will go onto that card. It's very cool to learn that knowledge is limitless but it's usually the 'jist' of an experience; we learn details. When we recall, there is this unconscious fabrication involved with explaining events we believe to be true and vivid recollections. Since we have only learned the important details, or purpose of an experience, our minds try their best to piece it all together in order to make a recollection appear seamless.

There have been studies of people who were on a polygraph telling unconcious fabrications that they believed to be true. Their brain waves and functioning appeared exactly the same as those who were telling the truth. So, I learned that eye-witness accounts and polygraphs are lousy evidence (~60% accurate). Hooray for our justice system. We respond differently to key terms, and "leading" questions can also affect answers as well. These are tests administered by and evaluated by people...

Anyways, back to me... I am the subject >_> I have been unable, for the life of me, forever... to recall events from the past correctly and I've always wondered, "Why?" I think I'm getting closer to my answer: my brain chooses to keep "important" information, and I guess I had no choice what I wanted to keep as a child. I remember trauma, pain, and some happiness. I'm assuming this is normal, but it can also be maladaptive. A classmate says he remembers near-death experiences when he was two. I am sure these memories were not removed during pruning because the brain acknowledged this information as important for later survival, "If i experience a similar event, I will use what I learned from it to survive" kinda mentality? I think. For me, I have jumbled routines as memories because that's basically what I have as my past. I cannot differentiate one day from another, my childhood was very monotonous (for me). I know it was fun, but as a teenager with depression, my emotions reinforced the memory of certain events over others.

I know something will trigger happy memories to resurface, but I can accept it not happening. I have learned to live in the present, and accept myself as all that I am. My past made me, but dwelling on the "why's" will not move me towards the "hows" I can improve.