A few further thoughts. My wife has a small circle of friends and meets up with them from time to time for meals, tea and cake, walks, gym sessions or just plain old chat. I can see that when she is retired this will continue (rightly so) which means I shall be home alone at regular intervals and it occurs to me that I may become slightly resentful. I haven't explained that very well, but she'll have a social circle while I won't. I hope that won't make me too insular. Easy to remedy, I know, but if you don't feel the need to devote time to friendships, it's not so straightforward.
We are not getting any younger and my thoughts occasionally turn to what would happen if I were left on my own. She was abroad on business last week and I decorated a room in her absence. I worked really well with just Radio 4 for company, but by the middle of the week I was starting to miss human contact and the checkout lady at the supermarket must have thought I was super-chatty. I was OK on my own during the day because I'm used to that, but I did miss my wife's company in the evenings as that's when we normally catch up on each other's day and deal with all the things that need discussion. I do have the boys for company of course, but none lives close by - in fact 2 of them live in different continents.
I have observed my MIL spend her 30 years of widowhood in complete isolation. She has almost nothing to do with her neighbours, she has no friends and she doesn't participate in any clubs or societies. And yet she doesn't complain, is quite happy and doesn't hold any of the odd sort of views that hermit-like people are apt to form. She has her children, grandchildren and her sister for human contact although none live close by, so it isn't regular or frequent contact. When I was younger, I thought it was a terrible waste of her retirement when my parents (now long since passed on) were on this committee, that committee, were members of this club and that club and did voluntary work as well. But here am I, 2 years into my own retirement, doing exactly what MIL is doing. And it suits me fine! So again, you can see how this thread is making me feel better about myself and my lifestyle.
Another point is that even after 2 years, retirement is still a bit of a novelty, so perhaps I haven't yet forced myself to face up to what I want to do with this third age of my life. When that time comes, I may well enter into activities that bring me once again into contact with people in a way that creates the kind of "friendships" I described in my previous post.
I have actually found it very cathartic to write all this down and I hope it is not too rambling to be of interest. There's a lot more I could say, but I'll save that in case the thread fizzles out here.