I frequently ask why with respect to the reason for the rules. If I'm going to be making decisions regarding enforcing or making an exception to the rule, I want to know what the spirit and intent of the rule is so that I can make a better decision. People often think I'm being confrontational.
I asked my wife's son once why he was doing something a particular way, and he told me. I said, "Oh, here's a much easier way to do that." He hemmed and hawed and said he'd rather do it this way, and I realized that the reason he gave me was true but it was not the real reason, which he felt shy or ashamed about. My way of doing the task wasn't going to accomplish his real objective.
I find that "Why?' is the question that people most often give a less than completely honest response to. As long as what they say is true, it doesn't matter if it's not the real reason, they still feel like they haven't lied. I think it's fundamentally about shame.
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"The cordial quality of pear or plum
Rises as gladly in the single tree
As in the whole orchards resonant with bees."
- Emerson