is the belief that TV characters are your friends a normal/expected behavior?

Yes, its normal in a Dementia patient. The TV, dreams and reality become all one and the same. My Mom was watching a Diagnosis Murder episode and told me the man, Dick VanDyke, wanted to talk to me. I told her she was watching TV, her response was, oh yeah.

Sounds like dementia - my mom thinks that there are people outside doing various things and that the national news reporters are next door. She thinks that commercials are real events and that Donald Trump lives in our home town!

you know my mom has her own 'thing' and I've read other posts with their parents have their 'thing'

what I mean is these made up stories. they have a wide range of ridiculous stories in their minds. 

I thought my moms stories were strange until I read some other peoples stories.

and its sad and shocking to listen to what they are saying because they do believe what they say is true.

as long as its not dangerous - you can just go along with it.

its good she'll be seeing a geriatric dr soon

She has some cognitive impairments that need to be diagnosed soon by a geriatric or a neurologist.