The Earth Laughs at World-Conquering Kings; Yuga-Dharma and the Remedy for Kali
यदा कर्मसु काम्येषु भक्तिर्यशसि देहिनाम् । तदा त्रेता रजोवृत्तिरिति जानीहि बुद्धिमन् ॥ २८ ॥
yadā karmasu kāmyeṣu bhaktir yaśasi dehinām tadā tretā rajo-vṛttir iti jānīhi buddhiman
यदा देहिनां कर्मसु काम्येषु भक्तिः स्यात्, यशसि च स्पृहा, तदा त्रेतायुगं रजोवृत्तिं प्राधान्येन विद्धि, हे बुद्धिमन्।
Bhagavatam 12.3.28 says that when people become attached to desire-motivated works and to fame, passion (rajas) predominates—this is characteristic of Tretā-yuga.
Parīkṣit asked about the nature of the yugas and their signs; Śukadeva answers by giving behavioral markers—how people act and what they value—so the yuga can be understood.
Use it as a mirror: reduce fame-seeking and purely desire-driven activity, and redirect effort toward sāttvika living and bhakti—service to Bhagavān without selfish motive.