Ancient commentators–like some modern students–were confused about why Telemachus should risk everything by going to sea in search of his father. Especially troubling in this is the fact that Athena sends him (since she already knows all about Odysseus anyway). This scholion explains the sense of the choice.
“It seems that the journey of Telemachus was strange first because Athena was creating danger to the youth, second she was removing him from the insurrection of the suitors, and third because she didn’t need to search for his father. But it was necessary that someone who was raised by women, was beset with sorrows and who had not yet at any point tested himself in speeches, become polytropos in the same way his father did, that is, to gain this quality by wandering and to share with his father in the killing of the suitors. The affairs of his home first were secured in the assembly when he roused the people against the suitors and second when he, after he taught the suitors to endure evils with his promises, he said “I will give my mother to a man” (2.223). The danger sharpened the interest of the suitors even more alongside his own eagerness.”
ἄτοπος εἶναι δοκεῖ Τηλεμάχου ἡ ἀποδημία πρῶτον μὲν κίνδυνον προξενοῦσα τῷ νέῳ, δεύτερον ἐπανάστασιν τῶν μνηστήρων ἀπειλοῦσα, τρίτον οὐκ ὠφελοῦσα τὴν ζήτησιν τοῦ πατρός. ἀλλ’ ἔδει τὸν ἐν γυναιξὶ τεθραμμένον, λύπαις τεταπεινωμένον, ῥητορειῶν οὐ πεπειραμένον οὐδεπώποτε, πολύτροπον γενέσθαι παραπλησίως τῷ πατρί, καὶ τοῦτο κερδᾶναι τῇ πλάνῃ, καὶ κοινωνεῖν τῷ πατρὶ τῶν κατορθωμάτων ἐν τῇ μνηστηροκτονίᾳ. ἀσφαλίζεται δὲ τὰ κατ’ οἶκον πρῶτον μὲν ἐπαναστήσας τὸν δῆμον κατὰ τῶν μνηστήρων ἐν τῇ ἐκκλησίᾳ, δεύτερον δὲ ταῖς ὑποσχέσεσιν ἀνεξικακεῖν διδάξας τοὺς μνηστῆρας εἰπὼν „καὶ ἀνέρι μητέρα δώσω” [β 223]. ἔτι μάλα καὶ τῆς ἐπιβουλῆς τῶν μνηστήρων ὁ κίνδυνος ἠκόνησεν αὐτοῦ τὴν προθυμίαν. ( Schol. Od. DEJMa 1.93b).