I discovered an interesting quote while working through 'Drawing on the Right Side of the Brain' by Betty Edwards. There is a side bar reference to a reference by Thomas Gladwyn on the Trukese navigators ability to sail to another island by '..imaging the position of his destination relative to the position of other islands. As he sails along, he constantly adjusts his direction according to his awareness of his position thus far.'
In contrast, the European navigator '..begins with a plan that can be written in terms of directions, degrees of longitude and latitude, estimated time of arrival at separate points in the journey.' which is then put into place and followed to a tee.
The point of the reference in the book was to highlight the difference between left and right hemisphere mode of thinking, but it works as a great analogy for the agile versus waterfall approach to development too. In fact, if you google 'trukese navigator' you will find it being used in reference to teaching, communication and management.
It reminds of Kent Beck's analogy of learning to drive a car by aiming the steering wheel before starting the car, as apposed to making corrections as you go along. What I like about the Trukese quote is that the other method stilled worked, and for certain people the 'big plan' works for them to, but the cost is very different and sometimes you discover America instead of India.