Scared I'll forget where I am?

Short answer: Yes. The very definition of 'irrational fear' is worrying about something you know probably won't happen.

We all worry about what we'll be like, what our lives will be like when we get old. I'm getting old just now, and it's still a little scary, but not like any of the things I worried about all my life. I worried about being poor, perhaps homeless, about being sick or unhealthy or disabled, about being lonely and forgotten, etc. but I'm not any of those things.

If your grandpa was a lifelong smoker and died of lung cancer, that would make you not want to smoke, right? His dementia should warn you to be careful driving. Though its fairly unlikely you'd have a head injury in a car accident like he did.

You KNOW it's not genetic, and that would be most worrying because there wouldn't be much you could do. I mean, if all your grandparents and both your parents died of the same disease, then you'd have a good reason to worry, right?

But ALL old people have some dementia. As I got older I found I had short-term memory problems, and sometimes they really worried m sometimes! At first I thought it was all that pot I smoked as a young man, but then all my friends had the same problems. It's just a normal part of getting old.