In his book "Fats That Heal, Fats That Kill", Udo Erasmus writes "When room temperature is just right , we tend not to notice. When it gets too hot or too cold, we perk up from our diversions, adjust windows and thermostats to make it so we can forget about room temperature again, then shift our focus to other matters again. Health is like that too."
Fitness is like that also. It is easy to rock along and even comment about all of the people running or walking the neighborhood. Some might even say, "I should do that". Some do. Then the day comes when the blood sugar is too high, blood pressure is creeping up, balance isn't there anymore and muscle weakness is noticeable. The doctor may pull out his prescription pad. Those things may have happened anyway. A healthy lifestyle is still our best defense.
I am reminded of the metaphor of the frog and the pot of boiling water. If you drop a frog in a pot of boiling water the frog will try to climb out. However, if you put the frog in a pot of lukewarm water and gradually bring it to a boil...well, the frog isn't going anywhere. It is so easy to be unaware of the gradual change and lose sight of a bigger consequence. Sometimes we have to deal with the hand dealt, sometimes not.