Charlie Brown lessons

My children have always been well spoken. We've never talked to them with baby talk. I think that for the most part The beautiful wife and I have taught them to communicate very well.
At 3 years old, Big sister tripped in a hole in the yard, looked up at us and said, "this yard is not conducive to running."
At her two-year check up, the doctor asked if Little sister talks in two and three word sentences. We had to laugh, she tends to talk in five and six word sentences. "Daddy, I want my chocolate milk," is one of her favorite sentences.
All this isn't leading up to me telling you how smart they are because they can talk, though.
The point is, we think we communicate with them very well.
So, we had to laugh when we were watching the Thanksgiving Charlie Brown. Big sister asks, "why do the adults sound like, 'wah wah wah wah?'"
The beautiful wife explained that it is representative of how children and adults don't understand each other very well and that often, that is what children hear when adults talk.
"I just hear, 'do this, do that, do this,'" Big sister said.
And now I'm thinking, if that's all I heard, I suppose it would eventually begin to sound like, "Wah, wah, wah, wahwahwah." In fact I know it does.
Maybe we need to rethink the way we talk to our children.