Another example comes along to destroy your false paradigm. I want to give endless credit to @musclemadness and Mary Duffy for their efforts, their video on youtube (from which this screenshot came), and the harsh reality check which comes from both (#musclemadness). In the video (https://youtu.be/3h1P58BIa2s) Mary Duffy performs some seemingly incredible feats, except they're actually pretty every day practices once you've implemented healthy behaviors and just... you know... lift weights, like I and the sum total consensus of science on aging has been telling you for the past 15 years. In her 70s she shows YET AGAIN that we need not accept the passage of time as some sort of divine ordinance that you MUST become WORSE.
There is always this intimidation factor which people have to get over. I understand it well. I wasn't an athlete growing up. I found that "lifting weights" wasn't for me many a time. I've worked with not a few people who end up giving up on strength training in exasperation because they can't seem to figure out how to work around their various orthopedic issues and train effectively without irritation.
But, I would simply challenge you to at once both think bigger and think smaller. Think bigger in the sense that you really can do this and more. Think smaller in the sense that you need not START big. Just start. The compounded interest of physiology doesn't rely on you lifting "heavy" (whatever that even means to you) today. It just relies on you stressing skeletal muscle with relatively challenging loads regularly. And that journey can be started at any moment, by anyone, in any tolerable manner, without equivocation.
Just look at Mary here.