From a cool blog called Mental Floss: The 15 strangest mental conditions.
9- Jamais Vu (Never Seen)
Jamais vu stands for a familiar situation which is not recognized. It is often regarded the opposite of déjà vu and it comprises a sense of eeriness. The observer does not distinguish the situation despite knowing logically that they have been there before. It is usually described as when a person shortly doesn’t recognize a person, word, or place that they actually know. Chris Moulin, a researcher at Leeds University, inquired 92 volunteers to write up “door” 30 times in 60 seconds. He accounted that 68%of his guinea pigs showed symptoms of jamais vu, such as starting to doubt that “door” was a real word. This makes clear that jamais vu might be an indication to brain fatigue.