You can't always get [someone to do] what you want.

This is one of many reasons that trying to get people to do something you want them to do for the sake of their health seems impossible to me. Since some of you surely won't read the whole article, I'll summarize: it's about a program being tested in which people can win money for taking their medicine. The three most powerful paragraphs, in my opinion, are these:
Before the program, Chiquita Parker, a 25-year-old single mother with lupus, too ill to continue her job with special needs children, repeatedly made medication mistakes, although she knows she depends on warfarin to prevent clots than can cause strokes, paralysis, or death. "I would forget to take it," and feel "like I couldn't breathe," she said. Or she would "take two in a day," and develop bruises from uncontrolled internal bleeding. But in the six-month lottery program, she pocketed about $300. "You got something for taking it," Ms. Parker said. Suddenly, she said, "I was taking it regularly, I was doing so good."
So, top boil that down: a woman who is unemployed (and therefore presumably has a fair amount of time on her hands) cannot muster the organizational skills and discipline to take a single LIFE-SAVING pill every day, but when the prospect of winning money enters the picture she suddenly thinks she "got something for taking it."
This is the real kicker, to me:
"We've made our best efforts to say, 'If you didn't take your beta blocker or asthma medicine, you have a greater chance of ending up with a heart attack or dead or hospitalized,' " said Dr. Lonny Reisman, Aetna's chief medical officer. "It's going to take more. It's going to take incentives."
The implication, I guess, is that "living," not having a heart attack," and "staying out of the hospital" are not really incentives, so stating the opposites as disincentives and then offering money as the only real "incentive" gets you out of the mess.

Results in two initial studies showed that many patients took improved warfarin use and that their blood-clotting levels stayed normal much more frequently.

Still, many said "the incentive had nothing to do with it," Dr. Volpp said. "They want to take credit for having done it on their own, not because somebody paid them," he said. "Most people on some level actually want to do these things. And we want them to feel like they did it on their own" to keep them adhering when payments stop.

But not everyone did.

"I really went backward," Ms. Parker said, after her participation ended. "I'm just forgetting all over again."

Really, Ms. Parker? Shocker.