Experts seem to have extraordinary memory in matters pertaining to their field. University professors read hundreds of papers, but can recollect a nugget of information they read years back. Chess players can recall entire games move-by-move from their childhood. Expert memory seems mystical to their students and people outside their domain.
And yet, the same people do not have great memory overall. They are just as likely to forget their car-keys, birthdays and anniversaries of their spouses or to leave the milk on the stove for too long.
Memory, therefore, is both domain specific and a result of training. Experts learn how to glean the essence from the information they peruse. Seasoned academics can summarize the essence of 10-page research papers into four to five bullet points. By sticking to what is important, their brain compresses all that information into a nugget that they store and retrieve at will. Their brain works much like a computer, zipping and unzipping information into their working memory.
On the other hand, as students and lay-persons are are much likelier to get lost in the details rather skim the essence of articles or research papers. What they read today remains fresh in their memory for a few hours but rapidly plunges as the weeks and months pass by.
People do not have “good” or “bad” memories – just trained and untrained ones. To increase one’s memory is to become great at gathering the essence – to summarize meetings, to take notes and to keep journals. While expert memory seems mystic, it is simply the effect of focusing on the essence in a particular field again and again and again.