I recently  watched a scene from an episode of NCIS Los Angeles.  Special Agent Kensi Blye was having a conversation with a young girl while they played cards.

 
The girl’s mother had died but before she did, she gave a note to her daughter, addressed to a man who the girl learnt was her father whom she had never met.

 
At some point in the conversation, Kensi asked the girl, ‘How are you sure he is your father?’ The young girl, who was also suffering from a form of autism, just shrugged her shoulders. After a while, when it seemed the discussion has been forgotten, she asked Kensi, ‘Did you know your father?’ To which Kensi replied, ‘Yes’. The girl followed up with the question, ‘How did you know he was your father? “Touché” I said out loud and my son who was also...