Our feelings are not as detached from our thinking process as it may appears. Our feelings are a result of what we have consciously accepted to be of value to us. Once we have done this we are automatically notified, through our feelings, if something threatens to undermine our values.
As values change so does feeling and sentiment. Anyone who has left the Witnesses has experienced this happening first hand. How we feel is a result of the choices we have made or experiences we have had due to choices others made that have influenced us.
Freud likened the unconscious mind to the horses pulling a cart. The driver is the thinking mind who stays in charge. The horses will do better with a good driver. Only in cases of extreme danger will the unconscious mind take charge and overide the wishes of the conscious mind.
To alter our feeling we have to examine our values and bring our priorities up to date.