My Christmas Eve and Christmas were very good this year. I did not once think of killing anyone, but I guess some people aren’t so lucky. Said Poirot,
The result of pretending to be a more amiable, a more forgiving, a more high-minded person than one really is, has sooner or later the effect of causing one to behave as a more disagreeable, a more ruthless and an altogether more unpleasant person than is actually the case! If you dam the stream of natural behaviour, mon ami, sooner or later the dam bursts and a cataclysm occurs!
from A Holiday for Murder