So this man, Ajāmila, was not a gṛhastha, because his beginning of life is that he gave up his married life. He was married with nice wife, coming from respectable family, but he gave up that, and he was attached to a maidservant. And he gave up his real family life. He became a family man with this maidservant, and go on begetting children. That was his life. Therefore this word is used particularly, tasya pravayasaḥ. He was old enough; still, he was begetting child. But one who is brāhmaṇa, he would not stay in family life more than fiftieth year. Pañcāśordhvaṁ vanaṁ vrajet. One must go to the forest. Forest means vana, and therefore, one who goes to the forest, from the word vana, it is vāna, vānaprastha. Prastha mean one who has gone. This is regulative life. One has to take leave from this family life and accept the vānaprastha. Vānaprastha means prior to accepting the renounced order of life. The husband and wife goes out of home and travels in many holy places to associate with holy man and take his instruction just to prepare for sannyāsa. So when one is fully equipped in knowledge, then he asks his wife to go to home to be taken care of by the elderly children, and he becomes a sannyāsī.
This is called varṇāśrama-dharma. This is real purpose of life: four varṇas, four classes of men, up to fourth class, not up to tenth class. And then spiritual life: brahmacārī, gṛhastha, vānaprastha, sannyāsa. This institution is called varṇāśrama-dharma: four varṇas and four āśrama. So when one is educated or trained up by this varṇāśrama institution, then his human life begins. Otherwise he is animal. One who does not take to this varṇāśrama-dharma, he remains in the animal life. That is the Vedic system.