I just got a flashback to a dream I had two years ago.

It seems I've been carrying that memory around in the back of my head for the last two years, but that memory was inaccessible to my conscious self as I had completely forgotten about that dream. I wonder how much junk we're carrying around in ow memories that we're unaware of just because it's not something we know that we remember and that we can recall at-will.
Something I experienced right now (I've just been doing homework) must have triggered that memory/made it accessible to me.