Ds was in it strong from age 3 until just about his 7th birthday. Ds also didn't respond well to "why do you think?" He really wanted to know. Part of it, I'm sure, was that he didn't have other great conversational openings. Once he figured those out, they did lessen. But part of it is, he's always wanted to understand. Today, at 10, he really wants to understand current events. (Try answering "why" for what's going on in Syria!) It's part of his personality.
Be thankful that he's got an inquisitive mind. Master the phrase "I need 5 minutes of quiet so my mind can rest. No questions for 5 minutes please." (and yes, be prepared for him to ask "why?" for that one too!)
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