this story is the same as what my cousin experienced, he retired early (at the age of around 35 years) now he is around 45 years old but there is an illness he is suffering from and he has to get proper treatment which quite expensive, so he sold some of his valuables and also withdrew his investment in shares.
as long as you can still make money, don't even think about retiring early, I know early retirement is everyone's dream but who knows what will happen next, you have to maintain your grades and productivity so that you stay healthy and respected by people.
I have also a friend that has aged 30+ and he got early retirement from the Armed Forces, he has a total of 12+ years of his job. But he took retirement very early, now he doesn't have any job and the pension which is issued by the government to him is very less and he cannot afford even his children's school fees. So, I have taken a lesson from his early retirement that early retirement is not a good idea, but If a person has some other business then it would be better for him. Otherwise without any other way of earning, taking retirement may lead to economic problems.
Wow! the cases you are describing are quite hardcore, and I agree that the thirties are not a good age to retire early. But I don't think the same for other ranges of age.
In my work there is a colleague that is in his sixties and just decided to quit early. That will suppose a big discount in his retirement pension, and many told him that he is mad, but he wants to enjoy the good years left, and I respect that. In Spain the retirement age is 67, and increasing, and some of us won't get to that age, so early retirement can be a wise decision in some cases.