They are not conscious of their mortality because they have been denying it all their life. 'Your grand pa did not ceased to be, he just went to a better place

They are not conscious of their mortality because they have been denying it all their life. 'Your grand pa did not ceased to be, he just went to a better place' is the lie they tell to their children, and in a minor grade, to themselves. All those 'life after death', 'angels', 'ghosts', 'zombies' and reincarnation movies and TV programs also help accomplish that. Now, you are not being pessimistic, just stating a fact. However, whatever the most average person can think should not and does not affect the way I see life.