Yoga sutra IV.14
“parinama ekatvat vastutattvam”
“Unity in the mutation of time caused by the abiding qualities of nature, sattva, rajas, and tamas, causes modifications in objects, but their unique essence, or reality does not change.”
We perceive changes in our external world but the real alterations occur internally within the individual and their perceptions change with time, so that it may seem an object has changed but it is only our perception of the object that has changed. The internal change within the individual perceiving the object may assume time has altered the object but time does not alter anything.
If you were to intensely observe a glass of water for an hour, a week and a year, you would come to realize that time has not changed the glass of water. The surroundings of the water has altered some of it’s characteristics. The rajastic effect would have caused evaporation, because the air takes in moisture reducing the amount of water. The tamasic effect would cause stagnation, the impurities in the water would grow changing the drinkability of the water. The water is still water but what we see is less water clouded by other organisms within it. Is the water still water. Yes.
The individual is the same. It is not the external changes that effect our reality, but internal changes the effect our perception of our reality. For example a person who can not read feels embarrassed and inferior they are angry and avoid any situation where they may need to read, or where it would become obvious to others that they can not read. They are uncomfortable around others , therefore they avoid contact with others and feel life is lonely and almost everything is a burden. Other people avoid them because they are always angry and this makes them uncomfortable therefore the person spends their time alone. The person learns to read and lets go of their anger, becoming more sattvic, or calm. Since they are more comfortable with themselves, they are also comfortable with others. This change allows them to interact with people and they do not feel inferior anymore. Other people enjoy their company and they spend less time alone. They no longer feel lonely and separated from others and enjoy life. Other people have a different experience of the person and feel comfortable around them.
The physical body of the person is the same, but their life is different. Though time has passed time is not responsible for the internal changes, because the person has more knowledge of themselves and the world around them, the internal nature of the person has calmed down and become more sattvic. The person’s perception of their existence in the world changed due to internal changes, but the world did not change. Other people may see them as different, but only their perception of this person has changed the person if physically the same.