For those looking for direction in life, I think I've found a method. Ask yourself what you are willing to die for, and live for that. When I pose the question to myself, the answer that immediately comes to mind is my children.
"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be." ~ Lord Kelvin