This is fair, and quite reasonable, I think. I'm a bit of an idealist about these things, and admittedly arguing more from the perspective of "it can't technically be ruled out" more than "there's a good chance it'll actually happen." If it ever does happen, I don't think it'll happen in our lifetimes.
LoL, I didn't take anything out, you addressed. I did actually substantially edit my second one, sorry in advance.
That's true. I assumed the serotonin thing was an argument related to my post, but there's a good chance I just posted before you got the chance to edit. I apologize for jumping to conclusions, and I appreciate that you've been so measured in response to my sperging.
But lobsters do age, don't they? Obviously they don't age the same way that we do, but they do grow from eggs into (delicious) adults. They eventually die due to being unable to properly molt, but even if there was someone (or generations of someones) assisting with molting forever, the lobster would grow too large to be able to consume enough calories to maintain itself. Death from old age just looks different in a lobster than it does a human.
Of course, research into how lobsters maintain longevity and regrow limbs would be incredible for medical advancements, but Bryan Johnson seems less concerned with that and more afraid that he's wasted his life and wants it back.
Whether that counts as aging is a matter of semantics, but I see your point, yeah. And more broadly: The more time passes, the more opportunities there are for non-aging things to kill you, so there really isn't any such thing as "immortality" even if aging were taken out of the equation. No matter how long you live, you're still dead at the end, which a lot of the "rationalist" types tend to ignore.
And yeah, Bryan is, at best, swatting at the epiphenomena of getting older, and when you look at actual old people, I'd say that having a reason to continue living matters more than pretty much everything else. People often take ill and die within a week of their spouse dying, or become terminally ill as soon as they retire, and because these things don't fit neatly in statistics, they're ignored. I tend to think that the things that make young people depressed make old people dead, and fretting about a healthy lifestyle is impotent worrying most of the time.