What I've noticed is that the people who didn't give a thought to limitations (other than a sizeable number of 'it's all in your head', 'just lose weight', 'just take a magic vegetable juice and drink vinegar on a full moon and then run a marathon every other day' comments) are the ones who are absolutely stunned after 40 when something suddenly goes very, very wrong for them.
Part of this would be due to their diet, whether it was mostly takeaways, fizzy drinks and chocolate (but 'fine' because they weren't overweight) or restricting hugely without sufficient nutrition because slim was the only acceptable aesthetic and developing arteriosclerosis/ osteoporosis / T2 diabetes. Some never gave a thought to posture or biomechanics and wondered why after twenty years of wearing ballet pumps that their ankle or knee has given out, their bunions are agony, that lifting and twisting with their back has resulted in a horrible injury or that they've now got the most awful frozen shoulder and cervicogenic headaches due to slumping forward on desks with shit chairs. Others have actively rejected medical intervention 'because all you need is a bit of sun, vitamins are just a moneymaking scam' and found themselves at 45 with osteoporosis and/or skin cancer. And some have developed autoimmune diseases just because they were always going to, it was just a matter of time, not anything that could be prevented. They aren't taking any of this particularly well, so I don't want to think of how they'll react when things like hearing loss, macular degeneration, Parkinsons or other things begin to affect them.
Because of my conditions, I've had to be aware of nutrition, I've had to be aware of ergonomics and posture, I've had to be aware of the importance of footwear and orthotics to keep the kinetic chain functioning properly. And as such, whilst I have the conditions I always had, I haven't added anything particularly spectacular to the list since, other than some hearing loss (despite wearing filters, these things do just happen to some - and I don't think Covid helped much) and I just go between flare and remission as I've always done.
The relevance I think is that you don't assume it can't happen, so you make sure that you maintain core strength and flexibility, wear good shoes instead of pretty/cheap ones, make sure you get your vitamin D, folic acid, floss your teeth daily, get your eyes tested and take a calm but proactive approach where physical health and strength is maintained more than concentrating upon appearance.