Does hypnosis really work? For BBC Future, Martha Henriques falls down a rabbit hole and explores hypnosis as a treatment for pain, anxiety, PTSD, and other conditions.

For many people, it’s a regular occurrence to get lost in a good book, or become so absorbed in a film (perhaps even a Harry Potter film) it can become overwhelming. Or perhaps you find yourself oblivious to landmarks by the road as you drive along the motorway. If that’s happened to you, then you’ve experienced something not so different from hypnosis, says Barnier. There are even parallels between becoming absorbed in your smartphone and hypnosis – both distort time perception, reduce awareness of your external environment, and bring a reduced sense of agency (that feeling you just can’t stop scrolling).

But if you don’t often experience these kinds of deep absorption, that’s normal too. “It’s just like the difference between extraversion and introversion,” says Barnier. “Some people are just living in their skins in different ways in the world.”

Cheri has been an editor at Longreads since 2014. She's currently based in the San Francisco Bay Area.