Usually when I am alone that is when I will reflect on my life, my future and the lack there of, that's when thoughts of death usually come up. Of course I think of plenty about plenty of other things when I am alone, it isn't like all my alone time revolves around thoughts of death, far from it. If I am with others I am usually occupying my mind with thinking of what I am going to say next since socializing doesn't come naturally for me.