What next? A practical problem.

I am trying to think about What next? I was just 69, I am in good health, my family responsibilities have lessened. As for my projects: Doing Physics came out in a second edition a few months ago; The Scholar's Survival Manual will be out this Fall; under contract, I am working on a second edition of my Doing Mathematics; and there is a book of my photographs of LA where the topic is how people and the physical city determine each other (much as in General Relativity, mass and geometry determine each other--that's what Einstein's equation of General Relativity says). 

I have some terrific possible courses to teach in the future: Defense Policy  and a sequence on Intelligence.

I could go on leave this coming year, and spend a semester as a visitor at two distinguished departments at other universities, related to my book projects. They are enthusiastic about my work.

Retirement is a possibility. I do not have an agenda or even a fantasy of what I would do otherwise.
 I just don't know how to think about this.