There is no better examples of evolving definition (during the lifetime of person) than the definition of right or wrong.
When we are little the definition of Right and Wrong is absolute. The adults define them (especially our parents). What the show as Right is Right and what they treat as Wrong is Wrong. That is the time when everyone see right and wrong as binary, the simpler times which our mind will ache for in future. Telling lies are wrong, stealing is wrong.
As we grow right around the time we start school, we learn that right and wrong are relative. There are little lies and big lies, little truths and honest truth. We learn to navigate this world with our friends and young foolish loves. This relative truths are based on the absolute truth from which we grew. Where in the absolute world a lie is wrong. In the relative world, simple and small lie here and there is fine. As long as it doesn’t hurt anyone, and it makes your life simpler.