I still find lots to do.
One aspect we had not considered was friendships.
Most of our friends are younger ( some a lot younger) and have a while to go before retirement. We find that we prefer to go away mid-week or non school holidays and this does not work for our younger friends. I look at it now as having the best of both worlds - we still go away mid-week and enjoy each others company (wife and I) and the serenity, but then still catch up with others for busier time slots.