What does the encounter between Rabbi Yochanan and Reish Lakish teach about reminding someone who has repented, a baal teshuva, of his past?

This source-based Torah study examines the question: What does the encounter between Rabbi Yochanan and Reish Lakish teach about reminding someone who has repented, a baal teshuva, of his past? The canonical Hebrew article develops the issue through the weekly Torah portion and the sources cited there. This localized discovery layer preserves the question and the source identity; it does not add any new halakhic, medical, legal, scientific, historical, theological, or empirical ruling or claim beyond the canonical Hebrew source.