Self-employed is great, isn't it? An alternate career (I've had several so far) could probably work for me too (although everything that comes in the door is "different" which helps keep the work I do fresh). Did lots of travelling earlier in my life and would love to do more: but have a couple colleagues who say this is quite doable now for reasonable periods of time with technology . . . may experiment with that too!
So cool that you're also still working, still learning and still enjoying both at 66!! Is there a reason why you'll soon need to stop? I'm seroiusly hoping (and expecting) to keep on working for at least 1o more years, and likely more!!