Unfortunately, some people have had the dubious distinction of having suffered injuries in multiple accidents.
Insurance companies have led the public to believe that these people are just malingerers or are milking the system. The insurance companies have focused on degeneration in a person’s spine (for example) and have mis sade it their mantra that a person who has “degenerative changes” in their spine are unable to suffer a subsequent injury. Nothing could be further from the truth.
Degeneration of the spine makes people prone to further injury. Such people are more fragile and can easily suffer a greater injury with less force. A minor car accident to a person with a health spine may result in no injuries. A minor accident with a person with degenerative changes in their spine could result in lifelong and debilitating injuries that require surgery, etc.
If a 1959 Cadillac still runs and is in reasonably good condition (considering its age) is hit on the side, you can be sure that the damage will be significant. A car that is 56 years old has some rust and all of its parts are somewhat loose, but no one can argue that the serious crush damage to its side can mean that it may never run the same way again.
A person born in 1959, in reasonably good health, will likely have the normal aging process in his spine. This does not mean that he can no longer suffer a terrible injury, but that person is likely to suffer more than a 21 year old athlete. The 56 year old who suffers a trauma will take longer to heal. The 56 year old will likely never heal as well as the 21 year old.
So when insurance lawyers pull the old trick of “degeneration = we did not cause this injury in this accident,” just think of the examples that I have given you.