Your description resonates with why I plan to gradually ease into "retirement." Being self-employed, I have more control than most as to how many hours I work. I plan to keep doing full time for another 3.5 years, then half-time for 3-4 years more, then drop to 10-25%, depending on what feels right at that time.

I figure this will let me gradually figure out how I want to make the most of the freedom of fewer commitments. It will also be more in line with my wife's plans, as she may want to keep working for the next 6-7 years.

One thing I'm doing now is launching a new very-part-time business that will have few time-specific requirements. It will let me work exactly as much or as little as I care to, from anywhere in the world.