Undergraduate / 'Envy and Diligence' - Common App Essay (Influential Person) [3]

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I'm new here, and I wanted some of my essays proof-read before I submit them. I think this one requires some changes though...
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Indicate a person who has had a significant influence on you, and describe that influence (500 words).

Envy and Diligence

My sister was expected to meet higher expectations than I, maybe because she was older. But at the same time, she was given more opportunities than I was. When I was seven and she was eight, my mom started teaching her piano. Although I complained that I could slam white and black keys just as well, my mom seemed to disagree.

"Oh, I'll teach you later, when you get older." I asked when "later" was exactly, and she told me that it was when I turned eight. However, a year later, I found myself bound to a never-ending chain of "maybe next year" replies. It was as if my mom told me that she will teach me music "when I was as old as my sister."

I wasn't intending to wait until "later" that would never happen. If she played piano with her hands, I could play with my feet. I bravely stepped up on the piano, quite literally, and perfectly reenacted my sister's scale exercises. I even added a little bit of improvisation to the boring scales by alternating my left foot and right foot, hitting both low and high notes. But rather than recognizing my prodigious aptitude for foot music, my mom locked me in my room for "reckless behavior."

My sister always used to rub things in my face by saying this: "I ate one more year worth of rice than you did. So I deserve all of this. Ha!" But what she failed to realize was that she ignited a desire in me to not only become as good as her, but better.

After numerous sorties of nagging my mom to teach me piano, I realized success in persuading her to teach me how to read music. I learned how the circles and bars between five lines came alive as beautiful music through the piano. But naturally, my mom focused more on my sister and eventually neglected to continue to teach me.

Determined to gain an upper hand on my older sister, I found myself in surveillance mode during her lessons. I started teaching myself, practicing day and night, not necessarily because I liked music but because I wanted to be better than she was. Gradually, I picked up music quite well and eventually surpassed my sister. Day by day, she was indirectly shaping me into a better person. To date, I enjoy playing the cello and piano, sometimes writing my own music. And now, I have gained advantages and success that my sister envies. She wishes she could write songs like I can.

Envy: one of the seven deadly sins. It was responsible for the first murder in human history, a Scottish couple's regicide, and the destruction of a great empire. But when it is directed well, it shows the way to one of the seven virtues: diligence. Then diligence pays off with great fruits. I am not angry at my mom and my sister; in fact, I am endlessly thankful that they have guided my immature childhood. Envy for me started out as a feeling of discontent and jealousy, but it became a strong motivator for me to push myself and even try to overcome my sister's advantages and success. Maybe envy is not so deadly after all.