Ever butt heads with someone with a concrete mind?
You know the kind....
They're minds are thoroughly mixed up,
and if that wasn't bad enough.
Their minds are completely set.
Can't change them, I bet.

I'm not talking the occasional set in your ways.
Everyone has those throughout the day.
It's the all encompassing kind.
That really sets my nerves to grind.

Won't ever look at another's point of view.
They think they're the only ones who have a clue.
Some people call them hardheaded.
A cement blockhead would be better stated.

JoJo Bean

http://www.poemhunter.com/poem/concrete-mind/