I find it fascinating how differently we age. This really came home to me several years ago when I attended a 30 year school reunion. We were all the same age (being the same school year) but as I surveyed the assembled crowd, it occurred to me that had I been asked to guess the age range within the room, I would have estimated a 20 year age range. A few looked truly fabulous (funnily enough these were the women who now lived in California, Colorado and New York!). Some of us (and I include myself ) looked very good for our age, and some, sadly, looked nearly as old as some of our former teachers who were also present.
I've always thought that one's genetic age is not necessarily the same as one's chronological age, and it seems that recent scientific research backs this up. There is something called insulin-like growth factor, and this escalates the ageing process. Short people are lacking this factor (which makes them short), but the brilliant upside is that we age more slowly . I am a petite 5' 0" and generally thought to be several years younger than I am. My paternal grand-mother was also very dinky, and was a ball of energy and youthfulness who lived to be 100+. Think about dinky people (Lulu? Kylie?) They offer evidence in support of this theory too.
Attitude is also a big factor in how aged we appear. I'm horrified by people of my age - and younger- who go on about being "too old" to do all sorts of things. Cop out! Very sad, but some people seem to like the excuse of age to not bother any more. Not me! I'll never be "too old"