We also suffer from a status quo bias, which makes us value what we’ve already got over the alternatives, just because we’ve already got it — which might, of course, make us react badly to new laws, even when they are really an improvement over what we’ve got. And there are more.

The crucial point is that in some situations it’s just difficult for us to take in the relevant information and choose accordingly. It’s not quite the simple ignorance Mill was talking about, but it turns out that our minds are more complicated than Mill imagined. Like the guy about to step through the hole in the bridge, we need help.

Is it always a mistake when someone does something imprudent, when, in this case, a person chooses to chug 32 ounces of soda? No. For some people, that’s the right choice. They don’t care that much about their health, or they won’t drink too many big sodas, or they just really love having a lot of soda at once.

But laws have to be sensitive to the needs of the majority. That doesn’t mean laws should trample the rights of the minority, but that public benefit is a legitimate concern, even when that may inconvenience some.

So do these laws mean that some people will be kept from doing what they really want to do? Probably — and yes, in many ways it hurts to be part of a society governed by laws, given that laws aren’t designed for each one of us individually. Some of us can drive safely at 90 miles per hour, but we’re bound by the same laws as the people who can’t, because individual speeding laws aren’t practical. Giving up a little liberty is something we agree to when we agree to live in a democratic society that is governed by laws.

The freedom to buy a really large soda, all in one cup, is something we stand to lose here. For most people, given their desire for health, that results in a net gain. For some people, yes, it’s an absolute loss. It’s just not much of a loss.

Of course, what people fear is that this is just the beginning: today it’s soda, tomorrow it’s the guy standing behind you making you eat your broccoli, floss your teeth, and watch “PBS NewsHour” every day. What this ignores is that successful paternalistic laws are done on the basis of a cost-benefit analysis: if it’s too painful, it’s not a good law. Making these analyses is something the government has the resources to do, just as now it sets automobile construction standards while considering both the need for affordability and the desire for safety.