Changes. Changes defines the value of existence.
If you have never changed anyone or anything, you practically never existed.
The very root of change is in changing thoughts.
could be a change in someone's memory,
or a change on how ppl think abt things
or a change in how ppl think abt doing things
or a change in how ppl feel abt things.
this is the reason why things changes and why ways of doing things changes, and that is a change in thought.