Everyone likes talking about himself. - Hercule Poirot - Agatha Christie

Oh, my dear friend, it is impossible not to give oneself away - unless one never opens one's mouth! Speech is the deadliest of revealers.

"She looked at them with shining eyes. Her chin went up. She said:
"You regard it as impossible that a sinner should be struck down
by the wrath of God! I do not!"
The judge stroked his chin. He murmured in a slightly ironic voice:
"My dear lady, in my experience of ill-doing, Providence leaves the work
of conviction and chastisement to us mortals-and the process is often
fraught with difficulties. There are no short cuts.

That's the curious part about speaking the truth. No one does believe it.