At fifty, one is still young enough to go on holiday twice a year, have a few pints at the local on the weekends or play golf all day long. Some may re-marry and start a new family. This all costs money. The bank balance will soon go into the red. Retiring early without the future possibility of work, and thus further income is a costly mistake.
Early retirement is to be avoided like the plague.
When it comes to health, if a human being has generally lived a salubrious life, chances are he will live to reach old age without any major medical complications. If this is not the case and a person has lead a 'full' life, it is probable that he will turn into a health liability in later life. Assuming health is not an issue, we must also consider the family situation. The basic survival outgoings of these examples are quite different. It won't take long for the former to run out of money and the latter to leave a healthy fortune in a will to the next of kin.