Everybody has a sixth sense. If someone is not good at lying, like little children, good observers will notice it. Very often they don't know how they know, but they know. Especially if they are familiar with the liar, like the parents, they will know. It can be by their body languages, by the tone in their voices, or more clearly, blushing, but it is noticed (subconscious). This is the sixth sense in action. "Something is not right."
Or it is not working properly now as all of us being busy with our life chasing “our goal”.
Cheers.