1. Chris Gardner was a homeless man portrayed in the film, The Pursuit of Happyness. He took an unpaid internship in a major financial firm, studied unceasingly while raising his two-year-old son, sleeping for a while in a public bathroom, but eventually emerged as a millionaire stockbroker. When asked how he had the strength to keep going, he said, "Find something you love to do so much, you can't wait for the sun to rise to do it all over again."
This is exactly the way music majors must feel about music. Many students feel this way; however, many are still not successful because their actions don't match their love for music. They lack the energy to relentlessly learn technique, expression, and interpretation.
2. Donald Trump once remarked, "If you don't have passion, you have no energy, and if you don't have energy, you have nothing."
Do you have energy to practice scales, listen closely to the music history repertoire, and work on your technical weaknesses EVERY DAY and often? If you do, you will be successful. If the love of music is there, but you regularly choose to do something else instead of practicing and studying music, you will struggle to become a good enough musician. Monitor your energy for developing musicianship - if you have it you will grow. If your energy doesn't match your love for music, the music major may not be for you (but music as an avocation certainly ought to be!).
(These quotes come from The Presentation Secrets of Steve Jobs by Carmine Gallo.)