It almost feels like someone has been erasing my memory

I just had the most weird dream except it didn't feel like a dream at all but a memory. I was at this compound but it was not just any compound. I know as in I know it so well I can literally draw the building schematics. I just know I go there every year for the test. I have no idea what the test is but I know I take it everywhere. First we have to go through hours of orientation then we take the actual test. And I remember how I learned to pick the lock of the apartments(where people go if they pass) so I can wait more comfortably until the start of orientation instead of being stuck with everyone else in the lobby. I even remember how to dodge the guards to get to the apartments, I remember the faces of the people assigned to my group I remember discussing with another candidate her respective field(which was bio engineering). It's just so weird. When I woke up I had this absolutely crystal memory and I know for sure that this has happened before and it will happen again but know it's slipping from me