It is not true... you have nothing to fear from insanity... it is a fallacy if you will it to be so...
L hid his face in his hands, stifling what might have been laughter, or tears, or something dizzy and desperate and in-between. "You make me insane, Light... I never know if I will live or die... I never can predict, or be certain... I never know if there will be a sunrise or a tomorrow..."