I think a question like this (the questions you are being asked by others Lillie) is asked either by someone who is old mentally or thinks like an under 30 who figures everyone over 30 is old. I've met people who were far older than me mentally and physically while at the same time they were a decade or more younger than me chronologically.
There are very few physical issues that are actually connected to age. For example, bad knees are more likely the result of some abuse in the past than due to simply getting older. Studies have shown again and again that remaining active results in remaining fit and capable of activities at pretty much any age. I just saw a clip on TV referring to a ski instructor in New York State somewhere who continues to ski daily and give lessons at age 90. Try telling her she's too old.
A sedentary life on the other hand is likely to result in physical limitations later on. Of course we are all where we are now and can't go back to change things. Those that are asking or suggesting you should be slowing down are the ones who are probably in trouble Lillie. At 65 (as of last week) there is nothing I cannot do that I did at 35, I just do some things a little slower and that isn't necessarily bad, ask my wife.
