Medicine for the dead is too late
Sayings designed to raise a laugh are generally untrue and never complimentary. Laughter is never far removed from derision.
A liar must have a good memory. -Mendacem oportet esse memorem
That which offends the ear will not easily gain admission to the mind.
Where evil habits are once settled, they are more easily broken than mended.
A liar ought to have a good memory.