How much complexity can humans handle? Preliminary answer: Not much. To be sure, some very bright experts in their fields can handle complex, seemingly contradictory notions. But few lay people can. This is a big, limiting factor in modern life.

An example came to the fore with COVID-19. People confuse what it means to “have” the infection. (1) You carry it in your nasal cavities but nothing more. (2) You’ve got it but are asymptomatic. (3) You show “mild” symptoms, some pretty bad. (4) You require hospitalization, even oxygen or intubation. (5) You die.

The “infection rate” includes all of the above. This is terribly hard to measure if you are at (1) or (2) but have not been tested. Because many early cases were diagnosed as “pneumonia” or something else, undercounting was prevalent. Some sufferers, looking up from their deathbeds, swore they didn’t have COVID, which they disparaged as a hoax.

Now, some hospitalized patients ask to get vaccinated, supposing it will save them. Physicians have to tell them, “Sorry, it’s too late.” Once you’ve got COVID, no vaccine cures it. Shots, after a week or two to kick in, block infection or at least fight serious illness.

Many follow the adage “Wait until it’s too late.” They don’t like shots, masks, the government or authority figures like Dr. Fauci. Some regret their stubborn, hyper-individualist convictions only when friends, family or they themselves fall ill.

And advice has been inconsistent, shifting from washing hands and scrubbing surfaces (largely ineffective) to masking and social distancing, which were discarded too early. Now, even those vaccinated should mask up in indoor crowds if they’re in a hot spot, which is nearly everywhere. I can’t blame people for feeling confused. I am among them.

For the next pandemic, likely a COVID variant, let’s set up a single, authoritative information clearing-house that issues weekly or even daily bulletins and best practices with the warning that they constantly change. The ultra cautious Centers for Disease Control and Prevention (CDC) was the wrong agency for usable, timely updates. Part of the problem is too many competing federal agencies and too little coordination among them.

But the deeper problem is human smarts, especially our limited ability to handle inconsistent, contradictory information, the “cognitive dissonance” problem that asks if we can hold two contradictory notions. Mostly, we can’t. One tends to drive out the other.

We like it clear and simple, something reality isn’t. This means, as Walter Lippmann and others argued a century ago, we must consent to governance by experts. Democracy enters with the firing of a faulty team of experts and replacing them with another team.

Many who oppose mask and vaccination mandates argue that people should make their own decisions based on their knowledge and judgment. But they don’t know enough for an informed decision, especially when they’re fed much misinformation. One story circulating on social media claims COVID shots make you magnetic. I tried it. Doesn’t work.

Not all decisions in a democracy should be subject to popular veto. They are part of the powers of a democracy to police destructive behavior. We demand vaccinations for school children and seat belts with some penalties for defiance. Normal. Necessary.

To be sure, some people make rational calculations about what is best for them. But they first get valid data. Now drivers are comparing their gasoline costs against the price of electric cars and the availability of charging stations. (My son, who loves driving electric cars, crunched the numbers for his situation and decided on a new conventional minivan, at least for a couple of years.)

Other complex areas may confuse even experts. Congressional bills insert what myriad lobbyists demand, making them so long and complex that few legislators know or care what’s in them. They leave detailed content to staffers. Actually, few staffers know the whole bill. The Senate’s current infrastructure package runs to 2,700 pages. And that’s the trimmed-down version. Unintelligible bills weaken Congress, give too much power to the executive and alienate citizens.

And sometimes even highly knowledgeable experts can follow the pack off a cliff, such as during the 2008 financial meltdown. A few started warning in 2005 that the housing market was frothy, but they were ignored. The market would straighten everything out. After the crash, the establishment closed ranks to ensure the survival and wealth of megabanks. Homeowners and savers were turned into losers.

Now massive federal spending — much of it necessary for COVID relief and infrastructure repairs — feeds record asset prices (stocks, houses, Bitcoins). Winners feel good, but what happens when the programs expire and the Fed raises interest rates above zero? Party over. Republicans vow to end the cash gusher after they win the 2022 midterms. Economists hope to do it gently so as not to spook markets. But today’s volatile markets spook easily.