Because I carry it with me all the time, I have become attached to it. e.g. If, on a particular day, you reach home late from office and your wife, who is angry with you, accuses of not being a family man and one who doesn't give enough time to her and the children. Your reasons for reaching home late may be genuine or not, your wife may be right or wrong on that particular day. In either case, you carry an image of yourself, all the time, as being a very loving, caring father and husband, who has been responsible for the all-round growth and development of the family in all respects since the family was created. Your wife's words basically pinch that invisible image, as a result of which you feel insulted and hurt and you react angrily, not necessarily in front of your wife, but it could be in front of someone else or even just internally.
This phenomenon happens many times, in various different situations with different people throughout the day and every day. The image that we all carry of our selves is made of various traits or characteristics, obviously the characteristics of each one's self-created image are different. These characteristics of the image may or may not actually exist inside the real self, but whenever someone challenges any of those characteristics or tries to suggest to us that one of those characteristics is not ours or does not exist inside us, we react.