Let’s play a game. Which of the following is a real smartphone-connected product?

A) A bottle that tracks your H2O intake
B) A bowl that tracks your dog’s H2O intake
C) An umbrella that reminds you not to leave it behind
D) A tampon that reminds you when it is time for a change

It is actually a trick question. All four of these “smart” items have either been announced by startups or are already shipping.

Technology has made our lives easier and solved some incredible problems, but a connected egg tray that reminds you to buy more? Come on. A subset of startups inventing the “world’s first connected [insert any noun here]” believe everything goes better with Bluetooth.

Blame the falling price of parts, the popularity of crowdfunding sites or the flood of cash into the tech industry. But if an object has room for a chip and a battery, some entrepreneur is trying to shove them in—and replace common sense with an app alert. The high water mark was reached last week, when startup MyFlow announced the smart tampon.

In life there are big problems and small problems. A connected pill bottle for seniors or an EpiPen case that sends an alert when someone goes into anaphylactic shock may save lives. A connected thermostat can save money; a doorbell can provide peace of mind. But many of these overpriced newcomers aim to solve problems that aren’t really problems. “Remembering to floss your teeth is hard,” is the first line of one product’s marketing video.

There is even greater irony: Instead of solving the hassles of everyday life, they create more of them. I’ve been testing many products that simply don’t work as promised. It is time potential buyers wised up to the Internet of Every Single Thing. Until the hardware improves and the ideas get more practical, it is buyer beware.

My egg tray doesn’t like my Wi-Fi network. That may sound like a Mad Lib, but I’m serious. It took me 15 minutes to correctly pair Quirky’s $15 Egg Minder with the iPhone app, which gives you a count of remaining eggs. Yet when I removed eggs from the tray to make breakfast, one of them remained virtually present. I guess you could say the app was… scrambled.

I washed down that delicious breakfast with nearly 15 ounces of water. But it happened to be one of the times the Hidrate Spark water bottle didn’t record it. What a waste of hydration! Later in the day at spinning class, my OMSignal smart bra only recorded half of my 45-minute workout. Because the fit of my preproduction bra wasn’t perfect, the sensors in the fabric didn’t always pick up my heart rate.

Most of the companies explained the reasons for the glitches—and that, with just a handful of employees and relatively limited funding, they were working on fixes. Will they actually get fixed? Hard to say. My review partner Geoffrey Fowler and I see these issues time and time again in our testing.

And I haven’t even gotten to the notification overload. Like the connected toothbrush and fork, it took some time to get used to my phone yelling at me to drink every few hours. Leave my living room just to go to the bedroom and my phone blares with alerts that I’ve left behind my connected $125 Davek Alert umbrella.

The notifications are a byproduct of a lack of real intelligence. A truly smart system could take into account your exact location, the weather, maybe even your schedule for the day, instead of just freaking out when your phone loses the umbrella’s signal. Perhaps a company like Google could pull off the ultimate artificially intelligent umbrella, but Davek, a small manufacturer of premium umbrellas? Unlikely.

Why try then? Is it simply adding tech for the sake of adding tech? “You wouldn’t buy a BMW because of the rearview camera,” Davek CEO Dave Kahng says. “The technology is there if you want to use it to keep track of one of the best umbrellas in the world.”

He’s right about one thing: It is one great umbrella. The smart thing should be as good—if not better—than the original. The $295 Raden A22 rolling bag doesn’t live up to that. The bag is stylish and has a cool built-in scale, but its battery takes up so much room I had to leave a pair of shoes at home. The company plans to release a bigger carry-on bag soon.

Also, the smart thing has to be better than combining the non-smart version with a plain old non-connected app. Take the MyFlow tampon, for instance. It aims to minimize menstruation leaks and the risk of toxic shock syndrome, an illness that can be caused by keeping in a tampon for too long.

Those are real problems for women, but do we really need to clip a Bluetooth contraption to ourselves for up-to-the-minute updates? There is no shortage of reminder apps—there is even the trusty Tampon Timer app. There is also that little piece of technology that has been around since the beginning of time: human sensation.

MyFlow founders say that apps are OK for those with predictable cycles but don’t provide the exact details that the smart tampon would.

Don’t get me wrong, we still need innovation in everyday objects. The BrunoSmart trash can is a great example. You sweep your schmutz right into its built-in dustpan and it is vacuumed up and dumped in the trash bag. If it works as shown, Dyson should be jealous.

Some smart product makers are starting to leave the smartphone integration on the table. Take the high-tech Juicero juice maker. “We decided turning the juicer on and off with the phone wasn’t necessary,” Juicero CEO Doug Evans says. Of course, he did still think it was necessary to build a $700 juice machine that won’t make juice if your Wi-Fi is down. I repeat: No juice if your Wi-Fi is down.

The Wi-Fi helps tell the machine how to best produce the juice depending on the ingredients, among other things, Mr. Evans explained.

But maybe I’ve never been more wrong. Maybe these connected products push ahead human progress and innovation. Genevieve Bell, a futurist and anthropologist at Intel, certainly opened up my eyes.

Ms. Bell reminded me of a time a little over a century ago, when scientists and companies began wondering what would happen if everyday items were connected to electricity or replaced with an electric option. The oven, the ice box, the clothing drying line.

“Like some of the experiments of 100 years ago, some are going to be unexpectedly interesting. Some will be hugely successful and change everything,” she says. “There will also be many experiments, as there were then, where we ask ourselves why? I’m sure in the 1920s and ’30s, it must have felt similarly overwhelming.”

Through that lens, it is amazing to live in a time of so much experimentation, where every day we can witness the evolution of what becomes—and provides value—as a connected computer. But let’s not let these inventions take away our own ability to remember events and mind personal matters.

After all, shouldn’t you already know anything your Bluetooth-connected toilet seat would like to tell you?

Stern, Joanna “Smart Tampon? The Internet of Every Single Thing Must Be Stopped” www.wsj.com. May 25, 2016. http://www.wsj.com/articles/smart-tampon-the-internet-of-every-single-thing-must-be-stopped