I would say success depends on having goals and achieving them, balanced with contentment and happiness. If a person is happy and content being a 40year old unmarried male living in his parents' home playing video games and working part-time at a video store (i'm just making this up- not a real person that I know of!) and just living in a virtual world- I would say this is NOT successful man. If a man became a multi-millionaire at the age of 40, has a gorgeous wife with 2 healthy and happy children but is completely unsatisfied- this man is NOT a success, either.

Success is, at the least, a very subjective term. But, IMHO, means balance.