I consider William Bridges “The Granddaddy of Transition Literature.” He was one of the first to identify the difference between change (something is different) and transition (you are different because of the impact of what is different). He pointed out that transitions begin with endings, followed by what he called “The Neutral Zone” when you may know what is changing or ending, but don’t yet know what is emerging.
Of the many books Bridges has written about transition, this is one I especially appreciate. Bridges writes of his deepened learning about transition in the decades after his first book was published, and especially during the time his wife became ill and died and his transitions after that loss.
If you’re interested in organizational transitions, you might appreciate Bridges’ many books about managing transitions in organizations.