When I watched that film I thought that such a syndrome would be extremely rare. Surprisingly the program revealed that 500,000 people in Britain have severe memory problems. Of course about 80% of these have dementia, so that they are not really functioning independent individuals like Leonard. However of the remaining 100,00 people, who have been affected mainly by viral encephalitis and head injury, many have few other symptoms. The people shown on the program were, indeed, very like Leonard in their determination and ability. Though not in rage and violence.
What struck me was that they were very positive people, struggling to hold their personalities together, but enjoying themselves minute by minute.
The memory problems varied: some clearly had almost no short term memory, but could lay down traces through constant repetition. Others could (for example) walk to the shops and remember what to buy, but their past lives were a complete blank to them. There was also a lot of use of note taking.
In all the documentary made me feel that Memento was less distant from plausibility than I had thought, and also made me think a great deal about what binds the mind together, and what happens when those bindings come loose.
PS Comic Book Guy: 'Most pretentious post ever.'