I have a lot of déjà vu. 4 or 5 times a month. Often when déjà vu occurs for me I'll remember having dreamed it. Often I tell my wife about those dreams if I remember them. Several months later I'll usually have déjà vu in which I'm doing exactly what I dreamed. Most times it's mundane things in life, but just last night I had déjà vu while sitting on the sofa with my dog and wife.
My opinion is that déjà vu is some sort of memory of your last life. I do feel we do this life ad infinitum, but each time it is different, if only slightly. Those moments of déjà vu could be moments in your past life that are exactly the same as now, and despite never having done or been around where your déjà vu occurs you seem to be remembering it as it happens.
I'd love some input on my 'theory' it's just something I've come up with to help myself explain why I always get déjà vu. Some people say they almost never have it. Maybe I just have a messed up brain.