Déjà vu

I think most people have experienced déjà vu, and an overwhelming majority of them would know the term that has found its way into many languages. One of my acquaintances has never heard the term. Confronted with it, she kept asking if it was someone's first or last name... she couldn't grasp the concept of déjà vu... and she was 62 years old. How is that possible when we are all surrounded by the same words, similar experiences? I felt embarrassed for some reason... she kept pressing trying to understand it, and yet couldn't... and there were more and more people there trying to explain. I am going to go home and teach this to my kids!