Well in this instance then, I'd recommend one of two things.
1. Journal your *visions* and keep looking back through your journal to refresh your memory of them. When the vision happens, and you now know it was deja vu--note it on the same page that you first journaled it. You may begin to notice a pattern. Plus, as you re-read the journal page every few days, you'll keep that fresh in your mind. You'll come to notice it as it begins to occur.
2. if you're like me and TERRIBLE at journaling things, just keep reminding yourself of the dream/vision you had and do the same thing as above, using your own mind as your journal. Not as good, obviously--but it can be done.
or tell a TRUSTED person whom will remember it. I do this as well--generally I tell either my husband, daughter or my sister in law, whom is more like a sister to me.
This reminds me of when I had a crazy dream about my neighbors. I remember in the dream the whole household was crazy upset and there was an ambulance at the home, and I was standing in my yard facing theirs just watching the whole scene play out. I remember seeing a bald headed, slender of build man being taken out on a gurney board and rushed to the hospital--sirens blaring! The rest of the family, specifically the oldest daughter, who is just a few years younger then me, was standing in the yard with her hands on her head by the ears and just frantically screaming, "OH MY GOD! OH MY GOD! NOOOO!"
Now, the house that I am speaking of belonged to the oldest daughters parents, however, they purchased a new home and allowed their granddaughter and her sons to move in here, when she was going through a divorce. At the time of my dream, the young granddaughter and her 2 boys were living there (and still do). But, that family is very close and they all live within 5 miles of each other--most within walking distance and this house is always filled with family and friends coming and going.
The man who owns the house (the grandfather) is about 70 yoa and fit the description of the man in my dream. I knew it was him and I realized he had a heart attack and was being taken to the hospital as a result and in bad shape.
I woke up from the dream not knowing quite what to do , because I could have it wrong and then they'd think I was a total nut job! So, I didn't say a thing.
However the day after I had the dream, didn't this scenario play out but not for the grandfather who owned the house--but his son in law. It was HIS wife that I saw screaming and in total distress in the yard. I never thought of her husband--but, he, too, is slender of build and balding. I had it somewhat wrong, as I jumped to conclusion it had to be the grandfather. And, it didn't happen at this house across from me at all, but at his own home just down the street, (another street from our homes) and the family were not in the yard screaming and having a melt down--but did inside their home, (as I was told by the daughter who is my age). In fact, after her husband had the heart attack and while waiting for her one daughter to come and pick her up to take her to the hospital, she also had a heart attack, though thankfully, not as bad as her husband--who ended up requiring surgery. Though, they were both put in the hospital and I never saw that.
so, we have these deja vu episodes, but some of it upon waking, we can also *adapt* to what we THINK it is and means. You have to sort of filter it.
I had one not too long ago that I shared w/my husband about the other neighbor next door to us. In this dream my hub & I were heading out late at night - and it was pitch black on our street. (normally is). As we were leaving our garage, I happened to look over to the neighbors house and we saw their 9 year old daughter sneaking out of hte house in her pjs, as if she were running away. In my dream, they had a deck on the 2nd level of the house w/stairs leading to the backyard, and she was coming down into the backyard that connects to our yard. In reality, they have no such thing. However, I wasn't sure upon waking if I should say anything because those neighbors already think I'm a bit weird as they found out I am a psychic-medium.
They wouldn't accept what I could tell them if it were to warn them. So, I don't say anything but at the same time, I can't help but to worry that perhaps the little girl MIGHT try to run away?
Its hard to know what to do, as maybe it was just a nightmare/dream. She is a very nice kid, and seems to be very happy at home and has doting parents. So, I am hoping it was just a crazy nightmare and I am not sharing it w/her mom. If I were to and it actually DID happen, this couple may want to charge me as a witch and have me burned at the stake like they did in Salem, MA hundreds of years ago....