We were there to discuss a technical implementation.
She kicked it off by saying "Let me start by asking a simple question, why do we do this function?"
I am now considered a domain expert. I love this question. It surprises me at how few people start with the why, or even can articulate the why.
The room of experts, were assembled to roll out a new product in their area of functional expertise. None of us had an articulate answer as to the why. She kept on asking. She gently challenged bad answers with a follow up why. Then when everyone gave up, she gave her answer as to the why. It was brilliant.
Always start with the why. Then ask why again. Keep on asking until you understand why.