Others have expressed skepticism at this story, where apparently the nine-year-old child wrote:
"Look. I know what you are trying to do. I know that you're worried about me. I know that you've been talking to a lot of people about my behaviour. But why do you want me to live my life the way others want? Life, by it's nature, is absolutely meaningless. Imagine yourself to suddenly wake up in a room, knowing of nothing, except the fact that you'll die within the next two hours. Would you attach importance to anything you would do during this period? Ofcourse not! All I know is that I am alive, a son of yours, on a beautiful diverse planet somewhere in the cosmos, and all I am interested is in knowing why did we acquire existence. This may be impossible, but I'd rather pursue the great impossible than spend my life living accordingly to the sentiments of people!"
And I think it's fair to be skeptical. The quote is quite specific for remembering a written down conversation. It kind of sounds more like something a 15 year old would say.
I guess this isn't a testable hypothesis, whether it's a troll or not is one of those things that might never be known.
But is there any kind of guidelines for assessing this thing, or how we should proceed?