The human brain generally does not have the ability of remembering long lists of unstructured items. We don’t remember well for a series of numbers, of nonsense words, or lengthy list of goods to shop in the supermarket. One of the pioneers of the memory research, Hermann Ebbinghaus made memory studies around 1885 on himself and tried to memorize nonsense syllables. Time to time he tested his memory, and realized that it decayed exponentially, and the performance of his memory is quantitatively can be characterized by what is called ”forgetting curve”. He also found that the his performance depended on the the number of items, it was more difficult to memorize long lists of items.
There are big exceptions. Some people literally are able to remember list of nonsense items for decades. Alexander Luria (1902–1977), a Soviet neuropsychologist studied a journalist, called Solomon Shereshevski, who apparently had a basically infinite memory. He was able to memorize long lists, mathematical formulae, speeches, poems, even in foreign languages etc. He was able to recall of these lists of nonsense syllables 14 years later as well that the day he had learned them. His performance did not depend on the length of the items, what Ebbinghaus observations and theory suggested,
Shereshevski was diagnosed with synaesthesia, which is a neurological condition, when different senses are coupled. When he realized his ability, he performed as a mnemonist. His ability implied disorders in his everyday life, it was difficult to him to discriminate between events that happened minutes or years ago.