Jamais vu is thought to be caused by a temporary malfunction in the brain's memory system. Normally, our brains store memories of our experiences in a way that allows us to easily recall them when they are needed. However, in the case of jamais vu, the brain may be unable to properly recall a memory, which leads to the feeling of unfamiliarity.
Jamais vu is often triggered by a stressful or emotional event. It is also more likely to occur in people who have certain medical conditions, such as epilepsy, schizophrenia, and anxiety. In most cases, jamais vu is a harmless condition that will resolve itself within a few minutes. However, it is important to see a doctor if you experience jamais vu frequently, as it may be a sign of a more serious neurological condition.