In the North American hemisphere flu season is here. Influenza, as most people know, is a serious respiratory infection that can be life-threatening in the very young and the very old. Some strains, as we’ve all heard about in the press in the past, are more deadly than others and may threaten even the strong. Luckily, however, we’ve developed a vaccine. It doesn’t guarantee you won’t get the flu: the influenza virus mutates rapidly and authorities must make their best guess about how to prepare a new vaccine every year, and sometimes they miss. Even when they get it right, you can still get the flu; you’ll just likely have milder symptoms and a shorter course.

While no medical intervention is 100% safe, the flu shot (for those not allergic to eggs) is pretty close. Yet every season, I never fail to have some of my patients refuse it. The most common reason I hear is, “I’ve never had the flu.” To this, I invariably say something like, “Just because you haven’t had a heart attack yet doesn’t mean you shouldn’t exercise.” I’d say roughly about half of my patients change their minds and decide to get the flu shot after I talk with them about it.

Over the years I’ve had numerous patients refuse my advice. It always bothers me — not because I like to think I’m right and my ego gets bruised, but because I genuinely believe my advice is in the best interest of my patients and I want them to do well. But over the years I’ve come to see that there are really two basic reasons patients refuse my advice, and that my response to them should be different.

The first is demonstrated by the influenza example above. There really are no good reasons to refuse a flu shot. It’s like buying cheap but good insurance: if you actually get sick or hurt, you’ll really wish you’d bought it. When you calculate the odds of being harmed by the flu shot and compare them to the odds of needing it and being helped by it, there’s no question that just about everyone should get it. It’s really that black-and-white.

So why do people refuse it? The reasons, of course, vary, but inevitably it comes down to a fascinating principle of psychology: we believe stories more than we believe evidence. It may be a story someone else told us about what happened to them when they got their flu shot, or a story we told ourselves when we got one in the past, perhaps that it made us sick (despite protests to the contrary, the flu shot cannot make you sick; just because one event follows another doesn’t mean the first event caused the second, as many people erroneously assume when they get a viral infection following a flu shot). Studies suggest this is because we find stories so much easier to remember — so much more cognitively accessible — than evidence. Even stories we tell ourselves based on no evidence.

I’ve evolved a general approach to patients who refuse my suggestions that tends to work pretty well: I ask them why they’re refusing. Then I address their concerns and explain the reasons why I’m recommending what I am, being as careful as I can to explain in as unbiased a way as I can what I think the consequences of their refusal are likely to be. I do this once. If they still refuse, then I accept their refusal without judgment and move on. Even when people make what I consider to be foolish choices, rarely does it pay to browbeat them into making the choice I want them to. Even if my reasoning is better than theirs, I have no absolute guarantee that the choice I want them to make will turn out to be the best (only a better — admittedly sometimes far better — statistical likelihood that it will).

I also respect my patients’ right to choose for themselves. If I’ve done my best to make someone understand that they’re about to jump off a metaphorical cliff and they still want to, I have no choice, I feel, but to allow them to do so (given that their choice isn’t in some way the result of a mental illness).

The second reason people refuse my advice is more subtle. Many medical choices aren’t, of course, as black-and-white as whether or not to get a flu shot. Even when the best choice for a patient seems relatively clear to me, I am presuming my patient and I share the same values. And this is clearly not always the case. Should we give chemotherapy if the side effects are likely to be severe and the expected increased length of life is only on the order of months? Should we give enough morphine to a terminal cancer patient to control her pain even if it means dulling her mind? Should the overweight diabetic give up sweets even though he derives enormous pleasure from having dessert just once a week?

To you reading this, the answers to these questions may be obvious. But I would submit that your answers will reflect your values and that not all people value the same thing. Further, what a person thinks he values may turn out to be quite different from what he actually does when he’s faced with actually having to make a choice.

As Daniel Gilbert argues in his book Stumbling on Happiness, we’re all far worse at predicting how we’ll feel and behave in the future than we think.

In the second scenario then, my primary aim is to help my patients understand themselves what they value and to guide them through medical decision making with their values — not mine — in mind. And in such cases, when someone makes a choice I wouldn’t make myself, as long as they feel it’s the right choice for them and I’m convinced I’ve clearly explained — and they’ve understood — the likely consequences, I’m able to support their decision without any reservation. In fact, in such cases, as far as I’m concerned, doctor and patient have both done their very best.

Alex Lickerman is an internal medicine physician who blogs at Happiness in this World.  He is the author of The Undefeated Mind: On the Science of Constructing an Indestructible Self.