Here's a mid-life career change article by Kathy Wild summarizing the process of reinventing yourself (each point below is abbreviated here - you can go to the article for the full description).
1) Restlessness, boredom and fatigue, even after a vacation.
2) The Call. Here we sense the possibility of a new journey beckoning to us. But "the call" is accompanied by fear of losing control, loss of the known and the comfortable and perhaps, the status associated with it.
3) The Awakening. Denial is broken. Emotional pain increases to the point that it can no longer be ignored.
4) Tug-of-War in the Twilight Zone. Feeling torn between the old self and the still unknown but "emerging" new self. Reflection, not action, is important at this time.
5) Emptying and Letting Go. Releasing old fantasies, expectations, and self-definitions that no longer fit clears the way for new perceptions and allows options to be revealed.
6) Rediscovery and Recognition. Acceptance of loss. Reconnection with the shadow self and a feeling of "coming home."
7) Reintegration and Renewal. The pieces begin to settle into place. Release of energy that has been held or blocked can now be directed towards the new.
I like the perspective this provides. I can definitely see it in my Passion Catalyst work (people generally come to me when they've hit that Awakening stage, and much of my work is helping them move through the remainder of the process).