I was raised by my grandparents. They were born in the 1910s, and grew up in the midwest during the dust bowl and great depression. My grandfather lost most of his buddies in Guadalcanal and Burma during World War II, and, in his own words, fully expected to become worm food himself. He said little, but one phrase he did repeat more than any other was simple: "Any day you're breathing is a good day." To him, every da…
It's been my experience that people who are unhappy or discontent try to "persevere" with trite mantra like "Every day you're breathing is a good day.".
My father used to say that a lot like your grandfather. And I suspect, like my father, your grandfather was dissatisfied and unhappy. He, like my father who fought in vietnam, probably also suffered through PTSD for his entire life from the horrible things he saw and did in war.
Honestly, if the only thing you can be grateful for is "breathing", then you might as well be a plant.
During the happiest times in my life, I've never even thought to say "Every day you're breathing is a good day.". It was only during the unhappy times in my life, that you have to resort to such quotes and mantra.