In this video Dr Catherine Ngahu talks about the power of commitment.
Committed people press-on to pursue their goals. The difference between interest and commitment is that When you are only interested in doing something, you tend to do it only when its easy and convenient, but when you are committed, you do it regardless of the challenges, you give no excuses; you only focus on results or outcomes.

Commitment implies that you push yourself, you hustle hard, and apply your skills and abilities fully to accomplish your goal. Hustlers keep pushing and don’t give up.

Commitment is the willingness to direct your energy, time, and effort to what you want to achieve. Its the readiness to work hard, and work smart to keep your promises to your self and others.Commitment goes far beyond interest or desire. While desire is important, many with strong interest and even clearly defined goals fail the achievement test, because they do not commit to doing what must be done, to get to where they want to go.