This video is about Clive Wearing, a patient with most severe case of anterograde amnesia ever known. He lost his memory 20 years ago, and the only person he recognizes is his wife. He can hold on to memory less than 10 seconds, so by the time he starts speaking second sentence, he has no idea what he said in the first sentence. Interestingly, he can play a piano, which indicates he retains memory before the amnesia started. This shows how important the short term memory is in our life.