Srimad-Bhagavatam: Canto 1 - Chapter 1 - Verse 2
नारद उवाचपाराशर्य महाभाग भवत: कच्चिदात्मना ।परितुष्यति शारीर आत्मा मानस एव वा ॥ २ ॥
nārada uvācapārāśarya mahā-bhāgabhavataḥ kaccid ātmanāparituṣyati śārīraātmā mānasa eva vā
Addressing Vyāsadeva, the son of Parāśara, Nārada inquired: Are you satisfied by identifying with the body or the mind as objects of self-realization?
This was a hint by Nārada to Vyāsadeva regarding the cause of his despondency. Vyāsadeva, as the descendant of Parāśara, a greatly powerful sage, had the privilege of having a great parentage which should not have given Vyāsadeva cause for despondency. Being a great son of a great father, he should not have identified the self with the body or the mind. Ordinary men with a poor fund of knowledge can identify the body as self or the mind as self, but Vyāsadeva should not have done so. One cannot be cheerful by nature unless one is factually seated in self-realization, which is transcendental to the material body and mind.