“No man has a good enough memory to be a successful liar”

“Liars ought to have good memories.”

“Success has always been a great liar”

“Me and Harry (Potter) are not very good with women. I've got better now. But I think any man whoever says he has never had an awkward moment with a girl is a liar. He's either a liar or he's delusional.”

“In either case the orator should bear clearly in mind throughout his whole speech what the fiction is to which he has committed himself, since we are apt to forget our falsehoods, and there is no doubt about the truth of the proverb that a liar should have a good memory.”
Vtrubique autem orator meminisse debebit actione tota quid finxerit, quoniam solent excidere quae falsa sunt: verumque est illud quod vulgo dicitur, mendacem memorem esse oportere.

“A good liar knows that the most efficient lie is always a truth that has had a key piece removed from it.”

“The fact that so many successful politicians are such shameless liars is not only a reflection on them, it is also a reflection on us. When the people want the impossible, only liars can satisfy.”

“We all do what we can, and it has to be good enough, and if it isn't good enough, it has to do.”

“There is no such thing as a good writer and a bad liar.”

“The truthful man is usually a liar.”