I have been thinking about this a lot lately because I have always been the person who couldn't sit still. I am now 62 and have begun to see that I get tired easier and have more aches and pains than I did four years ago. I find myself sitting down during the day way more than I used to. I also thought when I lost my job two years ago I'd quilt all day long and I don't find myself doing that. When DH has a day off we get some things done but he is so tired from job stress that we don't always accomplish much. I think mental exhaustion plays a part in our tiredness also. I don't deal with handling problems as well as I used to. Calling the phone company to get someone to come out and figure out why the internet isn't working properly causes a stress where it used to be just a thing to be taken care of. Paying the bills, going to the doctor or just cleaning the house seems like a chore for me now.