MUCH older than me (in her nineties) neighbour

Its my experience that people judge people by their own experiences. I spent much of last year looking after my very old very worried dog. He was quite happy and ok round the house provided I was there but really could not cope if I went out so i didn't. My neighbour suffers badly with back pain so she assumed that my staying in was due to illness or disability and would frequently ask how I was and was there anything her husband could do for me. In fact i was busy gardening and DIY ing. I think your neighbour assumes that everyone who lives alone is lonely and needs to do what she does. It was the same when I was widowed. people would tell me what they or their friends had done and encourage me to do the same.

My neighbour is always trying to get me to go to P.E. classes.
They are all in their 80's and 90's and do it on a chair. I have also been invited to numerous coffee mornings and afternoon teas where the best china comes out on a trolley with cakes that have taken a week to bake.
I just say," Thanks I'll consider it when I have less to do".
I've had to get used to people watchers knowing my movements I've even had phone calls saying they heard I have got new Glasses!
Don't take it personally. They think they are looking after your welfare.

Your post doesn't make sense. You say your neighbour is concerned that you sit in all day and must be lonely

Yet she clearly doesn't notice that you are out all day. So how can you complsin about a total lack of privacy.

I suspect that none of the other residents are the least bit interested in what you do with your life. They have just noticed you do not attend any social functions and just assume, without any investigation, that as the complex is full of retired people, if you are not socialising you must be sitting alone in your flat - which is clearly incorrect.

So relax, your privacy is complete, nobody is interested in you. Her remarks were mere airy persiflage when she happened to meet you. Sink back into your anonymity content to know that your alarms were unjustified.

Thank her for her suggestions and explain nicely that you do not have time for these activities right now, as you are out all day.

Then try to forget her kind suggestions - I am sure they are meant kindly.

That is what I am doing right now with two women friends who are both brimming over with ideas for where I am to live and what I am to do in my widowhood, since hearing that my husband has been diagnosed with cancer.

I have thanked them kindly for their concern, but pointed out that it is somewhat premature and not helpful at all right now, where we are concentrating on DH getting treatment and if we are lucky going into remission, so widowhood is not my primary concern right now.

It seems your objection is that you are seen as in the same age group as the other residents, the exclamation mark after chair yoga and the title of your thread.

Is it an area with mostly older people? If so then you can understand why people assume you are one of them.

I think many people do not see themselves as others do, being young of mind does not always show physically.

Oh, I missed that you 'couldn't respond'. That must have seemed strange to your neighbour.

“Total lack of privacy”?
You must have privacy or your neighbour would know you frequently leave your home.
I’m sure she was just being friendly.
Nothing to sorry yourself about.

What did you reply FrankandEarnest?
In that situation, in my neighbourhood, there would most likely be a cheerful reply about being out rather than sitting in alone, followed by a short chat about interests and a comment that they'd maybe drop into a coffee morning some time if at a loose end.

I do live in quite a friendly place.

I am sure the invitations and suggestions are kindly meant.
It can be hard to take a deep breath and join some new activity where you know nobody and these may simply have been an overture of friendly welcome.
Of course you don't have to do anything, but declining politely hurts nobody and leaves the door open if you should feel the need for company in the future. Its not intrusive to show good neighbourliness is it?
And bottom line is you can go out and do your own thing. They will soon realise you have your own life. Good neighbours can be worth their weight in gold and there are enough stories of loneliness and isolation in our later years to see this in a different and kinder light.

Obviously your neighbour doesn't watch your comings and goings too carefully or she would know that you're out for most of the day.

She is probably just trying to be nice. I'd have a chat and a coffee with her and explain that you're just too busy. She is probably the lonely one.

Maybe you are misconstruing concern and friendliness for nosiness FrankandEarnest. If you explain you don't want to join the groups as you have other things going on that should help. Don't undervalue a nice neighbourhood and friendly people, not everyone has that.