If all people in mature society are self-knowledgeables by self-deceivers,then law courts get closed for lack of litigants. And as law courts get closed for lack of litigants,hospitals and temples will get closed for lack of illnesses and weak-minds consecutively.

Self-deceivers are 100% precise in their word/s,voice/s and conduct.
Self-knowledgeables are just 99.999% precise in their word/s,voice/s and conduct.