Most parents, despite best intentions and out of sheer exhaustion, will at some point answer a child's incessant questioning with, "Because I said so, that's why."
The intent is for this answer to prevent any further questions from being asked.
It's meant as a conversation stopper.
It's a quick answer.
It's an easy answer.
And it's the worst answer possible.
When a child has the intellectual curiosity and confidence to ask a question and the persistence to keep asking until satisfied with the answer you provide, the last thing you want to do is resort to hierarchy, to "pull rank" as a parent and say, "Because I said so."
Because when you do, what you're really saying is, "I don't really know the answer, and I'm not confident enough to admit that to you."
Or, "I don't have a valid justification, but I'm the boss so don't challenge my authority."
Or, perhaps worst of all, "You're not worth the time it'll take to explain my thinking to you."
And if you don't see why "because I said so" is a less than ideal response, try replacing "parent" with "manager" and "child" with "employee" in the sentences above.
Now you see the problem, right?
When you have the privilege of being responsible for a person's well-being and growth, there's always a better answer than"because I said so".