If he loves an object, he loves it for the self alone, and not for the sake of that object. That self is the atma , the true self. But, when the pure love of the atma becomes tainted with body consciousness, and the senses hold sway, attachment and selfishness arise. This inevitably leads to sorrow. The body is impermanent.
Death is certain for all.
Even if someone were to live for a hundred years, he would still have to face death one day. Everyone knows that. Everyone is sure to meet death and so everyone may be thought of as among the dying. Yet, even though they themselves are dying, people feel sorrow and grief when thinking of someone who has died. It is as if death were a totally unusual and unexpected thing, rather than the natural conclusion that must come to all.