What does it mean to say "I have a clear conscience"? A lifetime is not enough to refine the meaning of this tranquility.

From the years I have lived, I gradually gather elements for a final conclusion, replacing some, searching for others, more suitable. I suggest to you a temporary formula.

A clear conscience belongs to one who can say: "I take what is due to me." "I accept responsibility for any harm I may have caused." "What I gain for my happiness does not take away from the happiness of others."