Background: Memory recollection and present-moment awareness represent fundamental yet seemingly contradictory temporal orientations that influence psychological well-being. While extensive research has documented the detrimental effects of maladaptive memory patterns such as rumination and the benefits of mindfulness-based approaches, the field lacks integrative understanding of how these processes interact to determine mental health outcomes. Objective: This study investigated the dynamic relationship between memory recollection processes and presentmoment awareness practices, examining their independent and interactive contributions to psychological well-being across clinical and non-clinical populations. Methods: A mixed-methods cross-sectional design recruited 450 participants (aged 18-65; 150 clinical, 300 nonclinical) who completed validated measures of memory engagement (Reminiscence Functions Scale, Ruminative Response Scale, Impact of Event Scale-Revised), mindfulness (Five Facet Mindfulness Questionnaire, Mindful Attention Awareness Scale), and psychological well-being (DASS-21, Satisfaction with Life Scale, Psychological Well-Being Scale, Connor-Davidson Resilience Scale). Statistical analyses included descriptive statistics, bivariate correlations, hierarchical multiple regression with interaction terms, structural equation modeling examining mediation through emotion regulation, and latent profile analysis identifying distinct integration patterns, supplemented by thematic analysis of semi-structured interviews with 45 participants. Results: Bivariate analyses revealed that adaptive reminiscence positively correlated with life satisfaction (r=.51, p