garyt1957 My FIL retired last year, and it was a difficult decision for him too.
If you've made it this far you're obviously a smart guy - plan, but don't WORRY. Life is short, and now you get to spend all of yours the way you want to.
Where in the country are you?
I'd recommend reading. It is probably going to be weird having 40 more waking hours per week to yourself than you used to - find something you're interested in and start reading about it. You'll find offshoots you also find interesting, and you'll never be able to read it all. Great use of time, and will keep you fresh.
Maybe a little light exercise in the morning, golf late-morning/early-afternoon, some reading, voila - life is good.