Do people with dementia remember hateful things they said to you?

Does your dad have dementia?
Has he been checked for a urinary tract infection? Sometimes the infection will change their behavior. His doctor can order a urine test to find out.

If your father's behavior has been like this for only 5 days I agree with Sue that maybe he should be checked for a UTI. A sudden behavioral change should always be investigated.

Katz, are you asking if your dad will remember what he said, or what you said?

If this is a sudden change in mental status caused by a UTI, then it's entirely possible that he won't recall the episode at all.

You had no way of knowing that your father's medical status had changed, did you? Learn as much as you can about his medical condition and tread cautiously if dad seems argumentative. If he has been diagnosed with dementia, read EVERYTHING you can about this disease, and watch Youtube videos by Teepa Snow on how to redirect.

Best of luck; I hope you come back and post about how this turns out!

This is not the first time. He sometimes says odd things that make no sense

Talk about crazy things they can say, "call the police to lock me out of my own house". She doesn't recall saying any of that and it happens often that says she doesn't remember any arguments or outbursts.She has become forgetful,suspicious and hides things and can't find them herself like a $50.00 roll of postage stamps. Oh how she loves to argue. She's in a NH now and threatened to call State to the administrator if the dietary didn't shape up and follow her renal/diabetic diet. His response was that he could make her life HELL. Not very professional for an administrator.