Harrr, I thought you are a least a good few years older than me but I am 70 on the 22nd Dec so your less than a year older than I am.
I am a year older than you but I still have all my teeth. 9 of them I paid for as implants but they were very expensive, much more expensive than my real teeth. We all have arthritis and screwed up bladders and some of us have hair. I don't know what color my hair would be if I had any. But most of me still works perfectly and I also want to grow old enough to be an embarrassment to my kids. I am almost there.
I figure by 70 I'll be done reefing...that gives me 20 more years. I'll probably be working and lifting buckets, etc. at work until I'm 60 and assume if parts don't give out I'll continue to do so. My wife and I are starting to think about the golden years, we want to travel, but we are also pet people and there is the cost of travel and pet/reef sitting.
I can still carry buckets, empty ones but buckets all the same.
If your parts don't wear out, you didn't work hard enough. I had 22 operations on worn out parts so far, and I'm not done yet. As long as Medicare wants to pay for it, I love operations. Great sleep.