I've had that exact sort of thing. Sometimes i just don't know where I am. where-ever I am, it just doesn't look right. I've even had it happen at home - suddenly I feel like i'm in a stranger's place and nothing looks familiar. Driving home and having to trust the street signs because I can't recognize intersections.

The flip side to it is that if I've been someplace once, I can almost always find it again. It's not so much about remembering directions as it is recalling the look and feel of the route.