My mom's personality changed a lot with dementia. After a couple of months she forgot she was a heavy smoker. Watching documentaries and sitcoms pre-dementia was replaced with aimless watch anything but not really caring about it at all. She lost a lot of self restraint so it was hard to go out to places because she'd make an insulting remark about a stranger. We tried anyway. This was all after she forgot who her children were so we were getting pretty late stage.