>>510207906from what I've read, one of the important things that happens while we dream is we are organising memories, like what short term memory gets to go into long term memory. It's easy to forget but, there are a lot of things like what you had for breakfast or where you parked today, that you can recollect now but with time you will forget it. The brain isn't like a hard drive where it's digital and we can recall and do a read, there are redundancies too, you will sometimes might have difficulty recalling something but then your brain "finds a way", much like when a path is blocked off and we find a new direction.
It's more like analogue rather than digital, where to preserve the memory it might be like a sound that has to be played, like if you wanted to copy a physical tape, rather than a file on the computer.
Anyway, this is a long way to say that on some level you already knew she was cheating, you conscious mind can put it to the back of your mind, but when you're asleep that part of your brain that was suppressing it might not be active, and the part of your brain that is has to decide what to do with the memories, because if it's a non-event, like you just overreacted to her or something, it's getting forgotten. But if it's something as important as your girlfriend cheating, then it's likely getting put into longer term, and potentially getting played along with the existing things (remember like to recall even the older memories they're being played too, and related, like a graph).
Also that's one of the reasons I think why eye witnesses are so unreliable, when people discuss what happened and they're playing back the memory, if it's during a discussion it can be potentially be corrupted by what other people are saying, like there is now a memory of this extra detail of the conversation mixed in with the recollection of what happened, and since it's adjacent (like a graph) then it just gets mixed in.
Anyway sorry that happened to you.
