A gṛhastha (grihastha; householder) is of two kinds . One who becomes a householder and takes the responsibility of the relatives, after practicing brahmacarya (celibacy), is called a sādhaka (sadhaka). And the one, who, after paying three kinds of ‘debts’ due in the life of a householder, goes away from his wife, children and property, and roams about alone, to attain salvation, is called udāsīna (udasina).
guṇāṇi trīṇyapākṛtya tyaktā bhāryādhanādikam
ekākī ystu vicaredudāsīnaḥ sa maukṣikaḥ.
According to scriptures, as soon as a manis born, he is bound to three kinds of debts. Much earlier, this had been mentioned in Kṛṣṇayajurveda (Krishnayajurveda). First, he owes to the sages, and teachers. That debt is paid through getting lessons from the guru and the practice of brahmacarya. Second, he owes to gods.By performing yāga-yajña(s) (vedic rituals with fire), he pays this debt. The third debt is to the forefathers. That is paid off, by getting married, and giving birth to children to continue the lineage–
jāyamāno vai brāhmaṇastribhiḥ ṛṇavān jāyate. brahmacaryeṇa ṛṣibhyo yajñena devebhyaḥ, prajayā pitṛbhya, eṣa vā anṛṇo yaḥ putrī yajvā brahmacārī.
The scripture-writers, however, would not let one become udāsīna, without performing his responsibilities. After becoming a householder — suddenly someone would feel vairāgya (vairagya;disinterestedness) and seek to get off — this would not be allowed by Manu. Without duely paying the debts of the sages, the gods, and the forefathers, if one tries to leave the house, he will be ‘fallen’. Only after reading scriptures like Veda(s), and performing brahmacarya, to pay the debt of the sages, and by giving birth to children, to pay the debt of fathers, and by performing dāna(dana; donation), yajña etc., to pay the debt of gods –one may become Udāsīna. Otherwise the scripture-writers would not permit one’s doing so.