Travel Memory: The Science Behind Forgetfulness When You Take a Trip


Why our toothbrushes always get left behind.

Chances are you’ve experienced that sinking feeling on the way to the airport: You’re forgetting something. Of that, you are certain. Of what, you are not. The tip–of–the–tongue sensation follows you through the terminal like a roller bag, all the way onto the airplane. Finally, as the wheels go up, it hits you: Your toothbrush is still in its holder back at home.

October 6, 2021

Toothbrushes tend to land at the top of travellers’ most–forgotten–possessions lists. But this has little to do with lax dental hygiene, says Ylva Østby, neuropsychologist and co–author of Adventures in Memory: The Science and Secrets of Remembering and Forgetting. We have a limited amount of storage in our working memory, the conscious part of our brains that deals with the here and now, she explains. Ahead of a trip, details like departure times, gate numbers and the weather in Waikiki clutter your neuronal capacity, which most research suggests maxes out at five to nine bits of information at a time. It’s the reason at least one travel essential inevitably gets left behind. 

Related: The Best Travel Accessories to Keep You Warm and Cozy This Winter

“If you’re a habitual traveller, all of these things become routine,” says Østby. The more methodical travel prep gets, the easier it is to commit the process to unconscious memory, freeing up room for other things. When done regularly, packing a suitcase can be like playing the piano or riding a bike – something you do without thinking. But add stress into the mix, and even frequent flyers can feel like something has slipped their minds. “I often have the feeling I’ve forgotten something when I haven’t,” says Østby, a glitch that she says can stem from a sense of not having complete control over everything. 

“The moment of takeoff might serve as a strong cue, because it’s kind of the point of no return.”

So why do we remember things when it’s too late? “Spontaneous retrievals can come about when we let our guard down,” Østby says. It’s why you think of someone’s name after the very important business meeting has ended. When the pressure’s off, the brain can flex its muscle. Contextual cues also jog the memory. “The moment of takeoff might serve as a strong cue, because it’s kind of the point of no return,” says Østby. So, if you recall the times that you realized you forgot something during previous takeoffs, you might just remember you forgot something – again.

Related: Do Snap‑happy Travellers Have Blurrier Holiday Memories?

Total Recall

There are many tools available for under–slept and overstimulated airplane brains. These tried–and–true tactics will help you stave off memory loss on your next trip. 

  • Write things down. “Writing a list is the best tactic for remembering,” says Østby. It outsources thoughts away from the head. And putting pen to paper also helps to reinforce things: Research shows that students who handwrite have fewer memory lapses than those who type notes. 

  • Set reminders. Make the most of alarms, calendars, push notifications and other digital tools. “You can also encode the intention to remember later with an external cue,” says Østby. For instance, plan to check for your passport when you put on your coat. 

  • Repeat, repeat, repeat. Repetition signals importance to the brain. Instead of checking your boarding pass every few minutes, try mentally repeating your departure gate number once you’ve passed security. Repeat something enough times, and muscle memory takes over.