One of the entertaining aspects of living in downtown Boston is to watch the doomsayers. Whenever a new development or a large undertaking is proposed, someone claims it will ruin Boston forever.

Back in the 1990s, it was the structure that later acquired that clunky name, “The Leonard P. Zakim Bunker Hill Bridge.”

A man in the Back Bay was in a dither, and he wasn’t the only one. “That thing will have eight lanes,” he scowled. He predicted that it would be a monstrosity, that it would destroy the river, that everyone would hate it.

We know how that turned out.

My own neighborhood of Beacon Hill has suffered from panic attacks. For years restaurants were denied wine and beer licenses because soused diners would surely go wild in the streets. Then restaurants could apply for a wine and beer license only after a year had passed since their opening. Finally, and we probably owe it all to Julia Child, diners protested enough that the waiting period was eliminated. Most people decided they wanted wine with a nice dinner. And things were fine.

Then several restaurants applied for full liquor licenses. This was a calamity, neighborhood leaders asserted. One restaurateur who had promised not to seek a full liquor license actually sought one. He won in court, and nothing bad happened except that he angered neighborhood leaders. Soon after, most neighborhood restaurants sought full liquor licenses. Residents claimed their property values would plummet, and Charles Street would become raucous. The world would end.

We know how that turned out too. Neighbors themselves showed up at the bars, property values rose, and no one complained about rowdy patrons. A better life for everyone.

We hear similar exaggerations from the presidential candidates (and from messages in my email’s junk box.) Remember how half the country was afraid of Ebola? It was way across the ocean, and Gov. Chris Christie basically imprisoned a woman who had returned from Africa. But no one in the U.S. got it.

Now it is the Zika virus. It seems prudent for women who might be pregnant to steer clear of infected areas, but apparently no one else is in danger.

More feared than anything is ISIS. To hear some candidates, ISIS is right now storming our borders and beheading us all. Marco Rubio roars he will deprive anyone suspicious he catches of those constitutional rights we have so lovingly protected for almost 250 years and throw those guys into Guantanamo. His roar is amusing coming from his baby face. We’ve gone that route before, and it lost us our souls.

Rubio knows his swagger will get some approval since anywhere from 40 to 90 percent of Americans, depending on who’s counting, are afraid of terrorists affiliated with ISIS, according to CNN, the Washington Post and the Washington Examiner.

Whatever happened to the “home of the brave?”

With more than 32,000 Americans killed in motor vehicle accidents each year, according to the Insurance Institute for Highway Safety, shouldn’t we be more afraid of getting into our cars?

Here’s what I’m afraid of—the dark, bears, airplane turbulence, streets with no pedestrians, staying alone in a rural area. My fears are mostly irrational. I treat them that way.

One theory—people have boring lives, so fear adds excitement. One piece of evidence is the many horror movies popular now.

Maybe people truly believe one building will destroy the neighborhood, or one new hotel will make traffic so bad everything will stand still. Maybe they don’t want change. Maybe they are right, maybe not.

With Wynn waiting for construction to begin on the Everett casino, the talk of how we will all become crazed gamblers has been redirected to complaints about how bad the traffic will be. Wynn and Mayor Walsh have worked things out, but Somerville’s mayor is suing. Maybe traffic will be terrible. Maybe it will pollute the waterways. Or maybe the growing popularity of Assembly Square will have more effect than Wynn.

Building even regrettable skyscrapers like Harbor Towers or what used to be called the Bank of Boston has not hurt the city much. Paul Rudolph’s monstrosity of a state office building, as badly kept as it is, has not destroyed Cambridge Street. Neither has the city been destroyed by the expansion of liquor licenses, the deregulation of Blue Laws, or the opening of medical marijuana shops. Marijuana shops actually might provide a bit of levity as we watch who goes in and speculate on what medical condition they might have.

Look back at the tragedies that occurred since the middle of the last century—the Kennedys’ and King’s assassinations. Viet Nam. Nixon’s crimes. September 11. Wall Street’s and the banks’ cheating that led to a crippling recession.

It’s what we can’t imagine that we should really be afraid of.