P.T.F.A. RETARD(S)
A P. T. F. A. RETARD(S) is someone who refuses to learn, even when it's right in front of them. They make everything harder than it needs to be.
He said he 'just didn't get it' after I showed him the answer 5 times.
She didn't know the math problem was on the board because she was texting her crush.
He kept saying 'I didn't know' even though I told him about the test 3 days ago.