Simplicity

After my company completed a job in Estonia, we celebrated at an expensive restaurant in Tallinn. When I wanted to relieve myself, I left the table and sought the facilities next to the cloakroom. There, I found two doors, each one marked by an equilateral triangle. One triangle rested on a flat side with the point up, while the other stood on a point, flat side up. The latter triangle reminded me of something female. Using logical inference, I decided to enter the room marked with the point-up resting triangle. I soon discovered my mistake, left the room with the resting triangle and entered the room with the standing triangle. [Introduction]