A career retrospective highlights your ability to communicate in addition to bearing testament to the logic and rationale of your career choices. Start with your first professional job (note: not your very first job ever) and talk briefly about what you learned from each successive role. Don't forget to touch on what attracted you to each new opportunity, culminating in the one you are currently interviewing for. Frame each job change in terms of striving for something greater, not in terms of running away from a crummy manager or company.