Déjà vu is a psychological phenomenon where a person feels an overwhelming sense of familiarity with a situation or experience that is actually new. This sensation can occur in various settings, such as during conversations, visits to places, or even while watching movies. It often lasts only a few seconds and can leave individuals feeling puzzled or disoriented. Researchers believe that déjà vu may be linked to memory processes in the brain, particularly involving the hippocampus, which plays a crucial role in forming and retrieving memories. While the exact cause is still not fully understood, it is thought to occur when the brain mistakenly interprets a current experience as a memory, leading to the feeling of having lived through it before.