Why your dreams feel real while they last

In a dream you can fly over your old school, talk to someone who died years ago, and wander through a house whose rooms keep rearranging. And yet, while it happens, almost none of it strikes you as odd.

The critic goes quiet

During REM sleep, the stage most linked to vivid dreams, parts of the brain involved in emotion and imagery are highly active. Meanwhile areas toward the front of the brain that help with logic, planning, and self-reflection are much quieter. The storyteller is wide awake. The editor has gone home.

That is why dreams feel real. The part of you that would normally say "wait, that makes no sense" is mostly offline.

Lucid moments

Sometimes that critic switches back on mid-dream and you realise you are dreaming. This is a lucid dream. Some people have them naturally. Others train for them with simple habits, like checking during the day whether they are awake: looking at a clock twice, or reading a line of text, looking away, and reading it again. In dreams, text and clocks rarely stay the same.

Keep a dream log

Dreams fade fast, often within minutes of waking. Keep a notebook or your phone by the bed and write down anything you remember before you move or check messages. Even a single image counts. After a couple of weeks, most people remember far more, and patterns start to appear.

Have you ever known you were dreaming while it was happening? Tell us what you did with it.