Sigmund Freud said this quote

The question of the purpose of human life has been raised countless times; it has never yet received a satisfactory answer and perhaps does not admit of one. Some of those who have asked it have added that if it should turn out that life has no purpose, it would lose all value for them. But this threat alters nothing. It looks, on the contrary, as though one had a right to dismiss the question, for it seems to derive from the human presumptuousness, many other manifestations of which are already familiar to us. Nobody talks about the purpose of the life of animals, unless, perhaps, it may be supposed to lie in being of service to man. But this view is not tenable either, for there are many animals of which man can make nothing, except to describe, classify and study them; and innumerable species of animals have escaped even this use, since they existed and became extinct before man set eyes on them.