Desire is the key to motivation, but it's determination and commitment to an unrelenting pursuit of your goal - a commitment to excellence - that will enable you to attain the success you seek.

This quote is saying that having the desire to reach your goal is important in order to stay motivated, but it takes determination and commitment to excellence to actually achieve success. Desire is the start of the journey, but it is only with determination and a desire to strive for excellence that you can truly reach the top. It is not enough to simply desire something; you must have a commitment to work hard and to continue striving even if you experience obstacles along the way.