Bhagavad Gita Chapter 6, Verse 43

तत्र तं बुद्धिसंयोगं लभते पौर्वदेहिकम् | यतते च ततो भूयः संसिद्धौ कुरुनन्दन ||

tatra taṁ buddhi-saṁyogaṁ labhate paurva-dehikam yatate ca tato bhūyaḥ saṁsiddhau kurunandana

O joy of the Kurus, there he regains the wisdom from his previous body and strives again for perfection.

Krishna explains how the practitioner continues to benefit from past efforts. 'Tatra taṁ buddhi-saṁyogaṁ labhate paurva-dehikam'—there (tatra), he attains (labhate) that (tam) connection (saṁyogam) with wisdom (buddhi) from his previous (paurva) body (dehikam). This means: when reborn into favorable circumstances, the practitioner regains the wisdom from past lives—they remember, they understand, they have insight from previous practice. Their past effort isn't lost—it comes back as wisdom, as understanding, as natural inclination. 'Yatate ca tato bhūyaḥ saṁsiddhau kurunandana'—and (ca), O joy of the Kurus (kurunandana), from there (tataḥ), he strives (yatate) again (bhūyaḥ) for perfection (saṁsiddhau). This means: with this regained wisdom, the practitioner naturally strives again—they're drawn to practice, they have the inclination, they continue their journey. This shows how effort accumulates: past practice creates wisdom, wisdom creates inclination, inclination creates continued practice. Your effort isn't wasted—it becomes wisdom, and wisdom leads you forward.