Remembering past experiences not based on visual memory, but by how you felt for specific period of time..?

I'm just curious as to how this may work/ seem possible. It's quite difficult for me to explain this. I find myself feeling a certain way(saddened, happy, frustrated.. doesn't seem to matter.. sometimes they're mixed emotions) over a lapsed period of time (usually months at a time), an emotional plateau of some sort I guess, which I believe everyone experiences. The thing is I can hardly remember images, names, conversations, specific details of events etc.. pertaining to the particular time period. More so, I tend to get some kind of d�j� vu that brings to memory the way I felt before. I hope someone understands what I'm trying to explain here, I don't really understand it myself lol.. sory Im just confused.