Let him also not omit his daily examination of conscience which is undoubtedly the most efficacious means we have for taking account of the conduct of our spiritual life during the day, for removing the obstacles which hinder or retard one's progress in virtue, and finally, for determining on the most suitable means to assure to our sacred ministry greater fruitfulness and to implore from the Heavenly Father indulgence upon so many of our deeds wretchedly done. (Papal Writings, Menti Nostrae, 23 September 1960).
A conscience is what hurts when all your other parts feel so good.
A clear conscience is usually the sign of a bad memory.