Why The Itstaraswrld Viral Video Is Trending Now

I don't know why, but it seems to me that Bob would sound a bit strange if he said, "Why is it that you have to get going?" in that situation. Thus we say: You never know, which is why. but You never know. That is why. And goes on to explain: There is a subtle but important difference between the use of that and which in a. I know it originates from "head shrinking", but it doesn't help me a lot to understand the etymology. Why are psychiatrists called that? Is it like "my head is swollen [from anguish, misery, stress.