What does it mean you dream about something that has already happened in real life?

I had a dream about my ex it was a completely random dream, but a week later I had another dream about the first time we ever met properly, alone. I dreamed everything that happened that night as it happened, even standing at my door saying goodbye. It was basically like watching a video of our night together? Is that normal or does it mean something? I really liked him but we had fallen out when I got a knew boyfriend, this was about 8 or 9 months ago. My ex and I were never an item but we were more than just friends, we didn't stop seeing eachother for any reason but we've recently started getting along again... I absolutely love talking to him and smile everytime i see his name? What do i do?