Sometimes life just doesn't make sense

In my mind, people get sick, act sickly/have symptoms, and then we find out they're sick. The bigger the disease, the more obvious it is that something's wrong. I mean, that's the way it's supposed to work, right?

Apparently this just isn't the way it works with cancer.

For those of you who don't know my Grandpa, he is strong, vibrant, full-of-life. He's 70+ years old and still works 70 hour weeks. He puts in hundreds of tomato plants every year, along with peppers, lettuce, carrots, potatoes, corn, and so many more. His garden is always immaculate, and his vegetables are always tasty. And out of nowhere he has stage-4 diffuse large B-cell lymphoma.

And last night we found out that Jason's Aunt Cindy has acute leukemia. Her symptoms? Nonexistent. She found out because of a routine blood test. Aunt Cyn is strong and passionate and charismatic and not at all sickly.

So how does this even make sense? It just doesn't.