If you work in the city long enough, it begins to deal with you on a personal level. Streets reveal their moods. Sometimes the signal light loves you. Sometimes they fight you. When you're hunting for a new building, you hope the city is on your side. You have to use a little bit of thinking--you might call it the process of elimination--and you need a little bit of instinct, but not too much of either. If you think too hard, you overshoot your target and end up at the Pier or the Tenderloin. If you relax and let the city help, the destination does all the work for you.