This means they don't really process the world around them. They see and live in it, but don't feel it. It's a sensitivity/intelligence thing. Must be a lovely life, it's much easier. Every rose has its thorns.
I'd have to disagree. I'm over 60 and basically healthy. I'm slightly overweight now and take one pill a day to control an enlarged prostate but that's it.
Now I absolutely process the world. I'm married, I had three children and have suffered the usual share of family dramas / estrangements. I've been made redundant, run my own business, struggled to make ends meet, seen my wife suffer health issues (brain tumor, ovarian cyst, knee damage, etc.) and made and lost friends. I'm atheist, socialist and paid both a mortgage and rent. I am currently enraged by the rise of fascism and terrified for my children's future but I wouldn't call that mental illness. I still sleep at night, get up in the morning, try to live a good life and make a difference in my community. I've never been in therapy and I have had times of deep sadness and times of immense joy.