I work on the third floor. I've always worked on the third floor (at my current job of the last four years). The other day I was in a meeting down on the first floor and after it was over, I began the hike back up the stairs. I exited the stairwell, walked the full length of the building and turned into what I thought was my cubicle before I realized that I was on the wrong floor. Somehow I managed to make a course correction before the cubicle owner realized that I was occupying their space.
Three days later, I found myself on the wrong floor a second time. Fortunately, the error of my way registered in my brain a few moments sooner.