My dad is remembering things that never happened. Is this a sign of dementia?

I'd have him checked for other things to see if he has a UTI or some other kind of infection. The doctor may be able to do some test in his office to see how his mental cognition is. It could be delusions or false memories. I'd let the doctor know what you are observing, so he can do the proper evaluations.

I was a little embarrassed a few months ago when I accompanied my father to the doctor's office. He was in good spirits and was telling the doctor a couple of stories of his younger days. I didn't say anything, but, told my mom when I returned. I was thinking that daddy had some false memories, but, my mom said, NO, he's right. Your dad did play minor league baseball! I never realized it. lol

As my Mother was getting up in years, I would spend a night or two a week with her. She loved to rock in her rocking chair and tell me stories of her youth. (Wish I had recorded them). As time went on, I noticed that her stories became confused - I would correct her about "her own" memories. Eventually, the stories became more and more nonsense and although she seemed to believe them, it was obvious she had become impaired. We took her to her family doctor who performed several tests and diagnosed dementia.

This could be what's happening with your Dad. You've come to the right place for help and comfort - regardless of the diagnosis. Hoping for the best, Janet