What's past is past. It's all over and done with.
No use looking back and regretting over the what-could-have-been. True, reminiscing brings back both fond and bad memories. But they've now become history. All the wounds and heartaches have long since healed. No point in digging up the past.
But thank you. Thank you for the memories. It will be forever cherished in my heart... and remain in the folds of my aging brain.