Just one person
Yesterday, Jason Kottke featured this tidbit from Kurt Vonnegut's eight rules for writing short stories:
Write to please just one person. If you open a window and make love to the world, so to speak, your story will get pneumonia.
Last night, I read this in 101 Things I Learned in Architecture School:
Design a flight of stairs for the day a nervous bride descends them. Shape a window to frame a view of a specific tree on a perfect day in autumn. Make a balcony for the worst dictator in the world to dress down his subjects. Create a seating area for a group of surly teenagers to complain about their parents and teachers.
Designing in idea-specific ways will not limit the ways in which people use and understand your buildings; it will give them license to bring their own interpretations and idiosyncrasies to them.
Design for just one person: it sounds easy, but it rarely happens.