Why would anybody make up something like "A Terrorist Plane Hit The Pentagon" when terrorists really did hit the WTC?

I mean, you think that the government thought that we would blow off the WTC. "Yeah, so they hit the WTC. So what. It'd be something if they hit the PENTAGON!"

No.

Making up a rumor like this would waste way too much time, money, concern, and, most of all, work, to bother with. A plane had to have hit the Pentagon. If one didn't, then nobody would EVER say that one did.