People understand cars. If they want to keep one a long time they know that in order to get a couple of hundred thousand miles on the odometer they’re going to have to take good care of the internal components like the engine, transmission, etc. They need to change the oil and other fluids and filters on a routine basis. They should get their car checked over by an expert mechanic yearly. And to keep that car looking good, you need to take care of the body and paint as well as the interior.
Just like your car, that physical body you walk around in, or your “earth suit” as I’ve heard it called, requires a good amount of preventive maintenance to keep it running properly. If you’re like a lot of folks who don’t take care of their car and it doesn’t last 200,000 miles, you can always buy another one. Not so with that body of yours; it’s the only one you’re going to get and you have only one chance to maintain it. When the human body passes 100,000 miles, or half it’s lifespan, its going to be a result of what was done or not done to it in those first 100,000. If you don’t take care of it when it has 30, 50 and 70,000 miles, it may get to 100,000, but almost certainly won’t see 200,000 miles.