I'll be 70 soon and noticed nothing at 44 but bloody hell, turning 60 was like flipping a switch - loads of aches and pains, all of which resolved themselves in time so I can't even remember them and, and - no my memory's very good.
Despite excellent diet and exercise I still turned up with a mild cardiomyopathy in my late 60s, but well-managed and symptomless now. Hearing, taste and smell excellent and I only need specs to drive. You can do bugger all about glaucoma except keep it under expert observation.
What I have noticed after recent lumbar surgery is just how quickly the senior body loses weight - several kilos in a week! particularly muscle mass, and I can't wait to get the thumbs up to go back to the gym.
As for looking old? I definitely look bloody tired right now, enhanced by the weight loss. Doesn't matter how good the skin is, it's never a good look on a skinny face.
Any lessons? Look after your back, quads and glutes. Lots of protein.
Also listen to your body so you don't miss the unavoidable.
It would be unfair to leave out an aspect of living in Australia which is the tax slug you get for not having private health insurance. So I have it, and some things happen more quickly.