I've been retired for 10 years now when I was in the mid-60's. Had a solo practice and just lost interest in trying to meet client demands that pushed me to my personal tolerance level limits. I wanted to walk out, and not be carried out.
Being retired, you don't have to deal with client or customer inquiries at what may be inopportune times for yourself.
But, if you like what you are doing, work part-time if it generates the income you need. And, you will still have more time for leisure activities.
Yes, seek out new things. I don't really like to travel anymore and deal with the packing and unpacking and waits in line at airports, but I find local places to take walks and do water exercise in an indoor pool a few days a week, and again, no worries about those interrupting phone calls.
Lots of state parks in Connecticut to visit for a few hours. Silver Sands State Park in Milford lets you walk near the water all year round. In the summer, I go to a local beach club and hang out.
I have developed a hobby of listening to different types of music and saving what I like on my Spotify Playlist and listening whenever I take walks or cook. I have accumulated thousands of songs, from rock, pop, ska, boogie woogie, surf rock, deep house, Spanish and French pop, Quebecois folk, American indie/folk, ragtime, whatever. Instrumentals are nice because you can avoid hearing stupid lyrics.
Yeah, I enjoy learning what others like and do, when I read the Boneyard. And, apply some of them. Learn some basketball too. Never really knew what a hard hedge was, or some of the complex defensive schemes were before I read the BY.
Hope I got a little more gas in the tank so I can continue doing what I am doing, or doing new things from the suggestions I read from others' postings.
BTW, though I don't play it, I've been told bridge is a great way to stay active mentally and to interact with others.