Unforeseen technological inventions can completely upset the most careful predictions, you must try to foresee the future you will face. To illustrate the importance of this point of trying to foresee the future I often use a standard story. It is well known the drunken sailor who staggers to the left or right with n independent random steps will, on the average, end up about √ n steps from the origin. But if there is a pretty girl in one direction, then his steps will tend to go in that direction and he will go a distance proportional to n. In a lifetime of many, many independent choices, small and large, a career with a vision will get you a distance proportional to n, while no vision will get you only the √ n distance .In a sense, the main difference between those who go far and those who do not is some people have a vision and the others do not and therefore can only react to the current events as they happen.
— Hamming on Hamming