Full context:   Modern research has moved beyond rigid stage-based models, such as Kübler-Ross's five stages, toward more flexible frameworks. One influential approach is Simon Shimshon Rubin's Two-Track Model of Bereavement, which focuses on both day-to-day functioning and the evolving emotional relationship with the deceased. George Bonanno's research further shows that most people demonstrate natural resilience, experiencing stable functioning despite significant losses, while acknowledging that grief can manifest as sadness, anger, anxiety, laughter, or even numbness.