Okay, so I was in this weird looking building, looking at this weird looking door with a weird looking sign that said “PLEASE WALK IN.” I stared at it for a moment, slightly confused, but I decided to do the courteous thing and obey the sign. So I walked up to the door and reached for the doorknob, but it was locked. And then I was even more confused. Why would they ask me to walk in the door and then not let me in? It really bugged me, and it completely ruined my whole day.