What I don't understand

I've always been taught (and I try to teach) that God will never give us more than we can handle. But I'm just so torn up about this:

I have a friend who in high school, developed Chrone's Disease. then in college, after a number of assorted health issues, had to have his colon removed. Now at the age of 25, just after finally getting his college degree, he has been diagnosed with cancer in his bile ducts, and after chemo treatments will need a liver transplant to stay alive. And that's only if the treatments work as planned.

My question is this: why does Satan keep picking on the same people? You would think if he picked on all of us a little bit, he'd spread to more people. But I guess he has a plot here, because although I consider myself to be a firm believer, this whole thing has DEFiNITELY shaken me.