Justin Bieber's song 'Been You' delves into themes of regret and longing in a past relationship. The singer reflects on the mistakes made and the realization that he should have appreciated his former partner more. With a sense of yearning, Bieber expresses a desire to reconcile and return to a time when things were good between them. Key moments in the song include heartfelt admissions of missing the person and acknowledging personal faults, which highlight the emotional depth and vulnerability in the lyrics.