Success should be something you do not just “kinda sorta” want to achieve, but something you must achieve. Generally, top achievers expect to be successful and consequently, they are. They are driven by a “have to” attitude, not a “want to” attitude.
If you have no concrete goals and you have been succeeding in spite of yourself, just think how much more success you could enjoy if you were to set your sights on a definite path and had a specific timeframe in which you expected to reach your destination.
It is true that you do not need to set goals in order to reach some level of success, but most professionals who fail to set goals reach a plateau and lack either the motivation or the direction to go beyond it. They are unable to move upward to a higher achievement status.