Personal identity is something, feature, behavior which is used to distinguish one person to another. A person is given an identity according to time he /she was born or place of origin or according to events that was happening at that time.
The complexity of personal Identity comes to when two people of same body size, colour , sex, place of origin and same time of birth, seems diverse in their behavior and thinking capacity. It this divergence of persons that help us identify differently.
The man cannot be the same all the time hence he/she cannot be referred to