In ancient times, there was a talented musician by the name of Gong Ming Yi. He adored music so much he would carry his Zheng (a classical Chinese string instrument) everywhere he went.
One day, when Gong Ming Yi was on a walk, he came across a beautiful green pasture. He noticed a cow grazing in the middle of the pasture and sat down to play his instrument. Gong Ming Yi wanted to serenade the cow in this picturesque field, so he strummed the most complicated song he knew. The cow showed no reaction whatsoever.
Gong Ming Yi figured the composition was probably too deep for the cow to understand, so he played another piece. This time, the cow glanced up at him, wagged his tail but then continued to graze mindlessly.
The musician then realized the cow would never understand his music. He was saddened by the cow's indifference to his talent...thinking his skills were not up to par. People would tell Gong Ming Yi that it was not that his skills were unimpressive, it's that the cow will never understand musicality. They insisted that the cow is simply dumb.
Gong Ming Yi replied, "It's not that the cow that is dumb, it is me who is dumb. I did not realize to whom I was playing music."
Moral of The Idiom: Not everyone will speak the same language as you, so do not expect them to understand. Don't expect everyone to see eye-to-eye with you. Know the people you are communicating with, it might not necessarily be their fault for not level-ing with you.
ORIGINAL IDIOM: 对牛弹琴