ब्रह्मचर्यं च षोडशाद्वर्षात् ॥ कZ_०१.५.०९ ॥
brahmacaryaṃ ca ṣoḍaśād varṣāt
And disciplined student-life (brahmacarya) should be observed from the age of sixteen years.
Because self-control is treated as a prerequisite for reliable decision-making, reduced corruption risk, and steadiness under power.