This is one of those things that will vary wildly by person. Some people are absolutely wicked smart in their 70s having had 7 decades to read, write and digest and reinterpret and reread information and some people are entirely mentally gone by that point.
It’s just like physical health, some people don’t do anything to maintain it and start decaying in their 30s and some people remain in amazing physical health into their 70s and 80s, and some people have something tragic happen that hobbles their health for the rest of their lives. You simply can’t make sweeping generalizations like you have
This is one of those things that will vary wildly by person. Some people are absolutely wicked smart in their 70s having had 7 decades to read, write and digest and reinterpret and reread information and some people are entirely mentally gone by that point.
It’s just like physical health, some people don’t do anything to maintain it and start decaying in their 30s and some people remain in amazing physical health into their 70s and 80s, and some people have something tragic happen that hobbles their health for the rest of their lives. You simply can’t make sweeping generalizations like you have