Having completed the evolution to the post-'career defines you world' - what some might call retirement but prefer the word transitioned, I can look back at the process and recognize certain realities that were hidden from view while living through the process.
I think one of the most illuminating - sort of a 'ah ha' moment - things I recognized is just how important the natural reduction in energy level as we age is in the whole process. It is well recognized that people toward the end of their careers tend to be less enthusiastic than when they began. Some of this can come from boredom - having done the same thing for such a long period of time. But I think energy loss compared to energy required is the biggie.
When we are in the full flush of our careers, we tend to work balls to the wall. This is especially true for the entrepreneur or the highly career motivated person. Our work life which dominates our persona is based on expending a lot of energy which we can do when we're say in our 40's. As we go into our mid-50's and beyond we find our natural energy levels declining. Yet our work life is designed on an energy burn rate based on our younger energy level. A person starts feeling tired and that feeling of fatigue increases. It manifests in a negative attitude toward various things especially those aspects of work that we are less than excited about.
This gap between energy needed and energy available continues to grow as we get older. Most people finally hit a wall and end up stopping what they're doing without any plan for going forward. This leads to the scenario we've all seen of some one retiring and going into a funk or worse. Now their energy level is higher than what they have available to do and they're frustrated again.
The key to resolving this is to determine what one wants to do in the post-transitioned state...easier said than done. In my case I've been lucky enough to find a number of things that I like to do each of which provides something different to me. I couldn't do all of any of these things and be happy. I need the balance of them. So I have travel which fulfills the type A part of my persona, I have my highly pared down work which provides satisfaction from using my skills, keeps me socially engaged in the world and adds to the ease of our finances, and there is what I call my 'solitude stuff', the things I do totally by myself including my hiking/exercise, meditation, writing, and cooking that fulfill my inner being and peace-of-mind.
Together these three 'buckets' as I call them give me what I need. The key is to make sure I put the right amount of energy into each. Too much into anyone and I'm out of balance and feeling stressed. Too little and I'm bored and not stimulated enough. When I have the right balance of energy (tied of course to my energy level now) going into the right buckets, I find each day to be nourishing and fulfilling...just what one wants from the transitioned state.