Inner voice is that voice inside your heart which tells you if what you are doing is right or not. It also guides you in your life.

Today I learned that, if that inner voice of yours is starting to hurt you then its probably a voice that somebody else kept in you. That person may have a very big influence in your life and the things they said and thought about you have manifested themselves in the form of your inner voice. If that voice is malicious to you, you must stop listening to it. That’s right, I just said that.
Also, look at what Gary said in this video. This inspired me very much to write this post because I feel that this is goddamn true.
Words to live by friends.