Lies, sometimes can be convincing, or not. When you get a person that is a lie, you have to second guess everything they say. They are unconving when they tell you that they don't hurt on the inside, they are unconvincing when they tell you that you are alone, because no one is ever alone. Everyone has someone. What is unconvincing is when someone has hidden motives and meanings behind them, and everything they do, so you can't convinve yourself to trust them. After a while, everything you say is unconvincing for yourself. Then you believe that unconvincing, the truth is best, because after a while, the mask that people wear, can't convince even themselfs that they are living in truth.