What is déjà vu: A paranormal phenomenon or a memory tool for your brain?

Most people have experienced déjà vu at one time or another, that eerie feeling that you've been in a situation before when you know that you haven't. But what is déjà vu? And why does it happen? Colorado State University Psychology Professor Anne Cleary, who researches human memory and specifically déjà vu, says the reasons are a lot more normal than paranormal. Cleary recently spoke with The Audit about what actually happens when you experience this memory phenomenon.