Different Images

Many people only want others to know them at their best. But what I don't get is why people lie to make themselves look better. Sure, temporarily it makes things better, but in reality it doesn't make anyone more attractive or better. It makes people ugly. People are all wrapped up in fantasies that they can't even keep their worlds straight. What I don't understand, is if people are such good citizens, why do they lie about who they really are?