I tried explaining 9/11 to an autistic 9 year old boy. It went as you would expect.

"So, tomorrow is September 11th, and that is a day when we remember a very sad and scary thing that happened." I thought he might be ready to think about the world outside his own head. "A scary thing happened?" "Yes. Before you were born, when Daddy and I lived in New York, some bad guys crashed planes into some big buildings and killed a lot of people." "They made them dead forever? How can we stop them from making them dead?" I said, "That's a great question, our country has been at war for a long time." This is when Ryan launched into one of his grand analogies, in which he gets so wrapped up in his own thoughts he completely derails his own simile. "They made them dead like when the Angry Birds dead the pigs and they..." This led to five minutes of babbling about Angry Birds. Someday I'll try again to tell you about the big, scary outside world, Baby, but for now I will cherish your innocence, your self-centeredness, your complete obliviousness. Sorrow can wait. Fear can wait. Knowing can wait. And I can hold you close and keep dreaming that you'll never have to smell that horrid smoke yourself.