Memories can be formed at three levels: molecular, cellular, and system. Long-term potentiation (LTP) is the basis of memory formation at the molecular level. It is a process in which the connections between neurons become stronger, and memories are formed. The memories then can either be lost or turned into long-term ones, if this synaptic strength is constantly increased or sustained.
Hippocampus plays an essential role in the memory formation process because it is the part of the brain where short-term memories become long-term memories. These memories are then stored in other regions of the brain. Therefore, the whole brain is involved in the memory formation process. Different brain regions store different types of memories and, although they are interconnected, each plays a specific part in memory formation.
Normal forgetting differs from amnesia in the way that the first type of memory loss is connected to occasional events, while with the second condition, people lose whole segments of memories. Therefore, one can call an absent-minded person amnesic if their memories are affected in a much broader way than in most people, and they tend to forget something that people normally do not forget. In addition, people with amnesia are often unable to form new memories from particular time points in their lives.
I believe that a memory that can record information objectively and accurately is better than a memory that can be updated to support newer levels of understanding, because the first type encompasses the second. If someone can record objective and accurate memories, it means that their brain can effectively form new synapses and maintain their strength. This ability can allow a person to update their memory to understand concepts and subjects of increased complexity.