Bings: It seems that some of your feelings of deja vu can be attributed to having dreamt an event or an experience prior to the occasion, although some deja vu experiences may be attributed to past-life memories, triggered by different variables.
I am sure this occurs more often to people than they realize. Much of one's perception is filtered through a myriad of thoughts & images, all of which clamor for one's attention & may inadvertently block clarity. While one may not recall the actual dream or some other experience connected to the deja vu, the feeling remains.
I have had similar experiences since I was very young. It would not be until during an experience or when I was actually in the particular place or setting of the dream that I realized I had dreamt it.
One of the most compelling instances of deja vu occurred after I arrived in London, England for a short visit. I chose to walk the city rather than use the public transport so I could see more of the city. I had a guidebook with me, but I didn't bother using it.
I loved London from the first I set foot in it. It seemed very familiar & I felt at home, but I do not recall dreaming about it. The odd thing was that I did not lose a sense of direction as I tend to get lost in my home town! I knew I would find a bookshop for the books I was looking for, & I did locate an obscure, dusty old bookshop with 2 of the books out of 3. I was thrilled because those books were not available in the U.S.
I recommend keeping a record of such experiences, writing of them as one would dreams. It would encourage one's consciousness to be more aware.