Unexpressed thoughts make a good percentage of our thoughts. Mostly passed as personal and under our control. But the truth is that the unexpressed thoughts are not fully under our control. They subside into us but subside actively in us. So, it is important that the unexpressed thoughts are also positive. Do not get comfortable by the fact that no one else is knowing those thoughts. The negative unexpressed thoughts opaque our expressed positive thoughts. Therefore, train the mind to generate always positive thoughts whether expressed or unexpressed.