What’s Really Happening When You Experience Déjà Vu?
Cool Article by Avery Hurt in Discover Magazine
Experts estimate roughly two out of three people have had the experience at least once.
One hypothesis is that déjà vu is a problem with memory.
Another popular theory is that déjà vu is caused by a timing mismatch or interruption to your ongoing stream of processing of a current situation.
Another theory is that déjà vu is caused by mini seizures. https://www.discovermagazine.com/mind/whats-really-happening-when-you-experience-deja-vu

