Have you ever noticed that very small children are brutally honest?
And it's not because they want to be brutal, but because they just say it like they see it. If they think you're fat, they tell you. If they think your feet look big, they tell you. If your breath is bad or you have a pimple on your face, they make sure you are aware of it. If you make them mad, they let you know and they don't restrain their anger until they're taught to restrain their anger. Perhaps this is why kids for the most part have no mental stress. They speak truth, even if it's not popular. Then they don't have to remember what lies they've told to cover up at a later time.
“If you tell the truth, you don't have to remember anything.”
― Mark Twain