We all came to this world to experience the
natural and artificial,
birth and death,..etc.
The beauty is we all arrive with all the required senses to deal with this world.

The ‘Appearance’ will make no sense, If the recipient of appearances did not exist. The first man on the earth will not make any sense to be called a man because there is no man previously existing to see him. The appearance has meaning only, when he was able to see and be seen. He has to become a subject as well as an object.

We all are aware that we appear and disappear from nowhere. To say simply, our ‘being and appearance coincide’.
Nothing and nobody exist whose very being does not presuppose a spectator. Hence, Plurality is the basic law of this earth.

The appearance has two conditions, First is the appearance of the world. Second is he himself should be appearing and disappearing in the world. In simple terms, there should be a world before his arrival and there always will be a world after his departure.
And
We all know our life span not only covers our life but also the time. The uniqueness of times, it varies according to age. A five year old child can live full five years but a boy in a teenage will experience 20-30 percent only coz the time runs faster for him compared to five years old child or 70 years old man

Finally,
‘We appear and disappear’ is nothing but “we are of the world and not merely in it”.