When the fact doesn't meet the theory then let go the theory. - Agatha Christie

But I know human nature, my friend, and I tell you that, suddenly confronted with the possibility of being tried for murder, the most innocent person will lose his head and do the most absurd things.

Youth is a failing only too
easily outgrown.

I suppose next time I come home I shall find you wearing false moustaches — or are you doing so now?'
Poirot winced. His moustaches had always been his sensitive point. He was inordinately proud of them. My words touched him on the raw.
'No, no, indeed, mon ami. That day, I pray the good God, is still far off. The false moustaches! Quelle Horreur!’
He tugged at them vigorously to assure me of their genuine character.
'Well, they are very luxuriant still,' I said.
'N’est-ce pas? Never, in the whole of London, have I seen a pair of moustaches to equal mine.'
A good job too, I thought privately.