Discussing and documenting lessons learned is mainly done to improve the incident response process for future occurrences. It helps the organization to better prepare for, respond to, and recover from incidents by identifying what was successful and what could be improved. Sharing findings across the organization ensures that the knowledge is applied to enhance security posture and prevent similar breaches. Root cause analysis is focused on identifying the underlying cause of the incident, while forensic analysis typically involves a detailed investigation to gather legal evidence after an incident. Chain of custody demonstrates that evidence has been controlled and handled properly, but it isn't a primary purpose for lessons learned in a post-incident review.