The Servo.write() methods starts the servo moving, and returns.
Aha, so telling the servo to move to position 180 will in fact cause the servo to do that, and then return to its dormant position once it reaches 180?
No, that's not what Paul meant. He meant that the Servo.write() call returns immediately. It doesn't wait for the servo to finish moving. When a servo is set to a position, it stays there until it is told to move to a different one. If you set a different position before the servo arrives at the first one, it starts to move toward the new position straight away.
General purpose servos don't have a 'dormant' position.