I do not know if there is really a solid common denominator. Full realising or cognizant of the fact you are not going to get out of this current condition alive might aproach one though.

Having to deal more with how things will ultimatly be distributed is perhaps another. Feeling that the mind is still pretty much intact may be another. Or whatever little was there in my younger days is still present. There are probably hundreds of the personal individual indicators. The only certainty is if you live long enough you will get old.

At my age of seventy since still in relatively decent health especally ..I do not feel exceptional but fortunate for sure. Just the other day it occured to me at some point I will have to turn in my drivers licence not knowing when right now. Hopefull done by myself well before it is absolutly required.Most vapourise here because our family physicians develop concerns and phone them in. I do not object to this policy as it is all too easy to kill people with a car.

Aging is always like a lot of things relevant as well. To a ninety year old I am young. To a teenager far past just being ancient. All too soon since time always flies quicker for the individual with age. There is a reasonable explanation for that. I wll be over the hill or around the bend. Preffering to not live so long that my life is no longer worth living.