Flashback. Does This Mean Anything?

I thought I had everything figured out. Wow, that sounded so melodramatic. Anyway, I have visions sometimes, very rarely, but they're always in dreams. They're always in black and white. They're always various still shots of the real event. Always something small and meaningless. For example, I had a vision of me walking down the hallway of a building when a person came up to me and started talking. A month later, it all happened exactly like it did in the dream, except not in black and white, and it wasn't still shots. Regardless, recently I had something different. I experience a lot of flashbacks, but they always have triggers. (For example, smelling a certain cologne will give me a flood of memories of an ex-boyfriend of mine) And the flashbacks I have aren't like they are in movies or video games. It's just a flood of memories, and when I'm remembering them I can't move or talk. They happen pretty regularly, so I've just learned to live with them. Nothing big about it. But a few days ago I was at a friend's house. It was noon, bright outside. Beginning of August so it was hot. I opened the door for to let her dog out, and all of a sudden it wasn't August. It was like I was transported to a different time, because for a few seconds after I opened the door, it was darker than a black crayola crayon and there was snow covering every inch of the ground. Something else that was strange, it wasn't cold. It still felt like summer when I opened the door. Then it snapped back to August. It was terrifying, does anybody know if this could mean anything?