He actually does have a point. It's pretty difficult to actually reverse aging once it has started, as everything kind of feeds back into itself. There are a few exceptions- Alzheimer's may be reversible, but things like heart damage, immune weakness or DNA degradation may not be. The way it looks right now it may be easier to stop aging from starting than to stop the damage from occuring. Once it starts happening, even if aging stops the damage will still accrue.

From a computational POV DNA damage should be trivial to repair. You have so many redundant copies in your body. Of course building a fault-free copy, creating stemcells from that and coaxing those into fixing any defects without causing cancer is still scifi, but not the physics-violating kind.

" It's pretty difficult to actually reverse aging once it has started"

As far as I know, there are two paradigms about ageing: There is a biological clock inside us or it's only entropy acting (damage accumulation).

Both would start in the moment of conception. So, what it means "once it has started"?

> things like heart damage

Could be reversed with a heart transplant?

Today is my 40th birthday. sad face.emoji

Happy Birthday :)