Denial is the failure to acknowledge an unacceptable truth or to admit it into consciousness.  It is used as a defense mechanism. 

One can deny feelings, be they physical or mental.  

One can deny reality, no matter how stark.  

One can deny responsibility, no matter how significant.

One can deny pain, no matter how prolonged or intense.  

I could go on, but I'm sure you get my drift and that you might relate to it.  

We have all done it and the real questions are the consequences?