Certainly, our memory abilities are far below what would be required to remember all the new information we are exposed to in everyday life. Normal, unimpaired people commonly report difficulty in sustaining attention and retaining new information, as well as being easily distracted, frequently forgetful, exercising questionable judgment, and having poor planning skills. The everyday level of thinking and memory errors experienced by people who do not have a brain injury is the base rate of these problems in the general population. A number of recent studies suggest that the base rate is relatively high. 1 Similar frequencies were observed for other symptoms of mild head injury, including headaches, memory disorder, confusion, sleep problems, and nervousness.
Imperfect brains Having an imperfect brain is the natural state of affairs.
After all, evolution has been working on the human brain for only a few million years, and our memory and cognition systems are still evolving. In addition, over the millennia, the increasing complexity of human society has exponentially increased the demands placed on the brain systems that keep track of new information. This has created a great discrepancy between the amount of information we are expected to know and the amount we can remember. Presumably, that explains why, in studies of the base rate of cognitive impairment, so many people report frequent errors of memory and judgment. Most people, however, do not ponder the significance of their errors, accepting them as normal human imperfections.