Take magnets. This one has lasted because it started with a real detail. Traditional hard disk drives stored data magnetically on spinning platters. But despite a common belief, household magnets can’t erase them. Writing data to a hard drive requires a controlled magnetic field generated by the drive itself at extremely close range. A device called a degausser can wipe magnetic media, but you won’t find one in the junk drawer. And with today’s solid-state drives, which store data as electrical charge in flash memory cells, magnets are irrelevant.

A related myth is the notion that deleting files erases them, something you might do when you’re getting ready to turn in a laptop or phone. But it’s not enough. When you delete files, your operating system removes the file’s reference and marks the space as available, but the underlying data remains until something overwrites it. If you are selling or donating a device, back up what you need, sign out of your accounts, then use the built-in erase or factory reset option to make sure your data isn’t passed along.

Similarly, private browsing is really not so private. Also called incognito mode,  sites you visit are not saved in your browsing history, which is useful when using a shared computer. However, you are not anonymous to websites, your internet provider, your employer, your school network or any service you sign into. If anonymity is the goal, that takes different tools and a lot more effort than opening a private tab. Tools like VPNs, Tor browser and Proton email are built for anonymity, not Google Chrome or Outlook. 

Do you still regularly close all the apps on your phone? Many people do because they think it will save battery life. Apple has made it clear: Quitting does not save battery power. Inactive apps are usually suspended when not in use. Force-closing them and reopening them over and over can make the phone work harder because it has to reload the app’s data every time you reopen one. If your battery is draining too fast, the culprits are usually screen brightness, a weak signal, running video, navigation and location services.

Battery myths in general are common. One of the most popular says you should let your phone battery drop to 0% before charging it to reduce wear and tear on the battery. That advice belongs to older battery chemistry, not the lithium-ion batteries in today’s phones and laptops. In fact, repeated full drains add wear.

A related myth is that charging overnight degrades the battery. Today’s charging systems are designed to taper current as the battery fills and manage the remaining charge. The bigger issue is heat and time spent at very high charge. That is why optimized charging features minimize these stresses. 

Finally, there was a time when people ranked digital cameras and phone cameras based on the number of megapixels on the specs list. Megapixels tell you image resolution, not image quality. They do not tell you how much light the sensor captured, how good the lens is or how well the software processed the image. That is why one phone with fewer megapixels can still take better pictures than another with a bigger number on the box. In phone photography especially, software now controls much of the finished product, so look at all of the camera specs and compare output. 

So what should you do with all this? Worry less about magnets. Worry more about proper device resets before resale. Use private browsing when you want less evidence left on your own device, not when you want to be anonymous online. Leave your apps alone if they’re open. Charge your phone when it is convenient. And when you shop for a camera, look at all of the camera components, along with the photos under differing conditions like light levels and motion. Consumer tech changes fast, but bad advice does not. 

Leslie Meredith has been writing about technology for more than a decade. As a mom of four, value, usefulness and online safety take priority. Have a question? Email Leslie at asklesliemeredith@gmail.com.