You spend years asleep. He learned to wake up inside it.

Every night you go somewhere. Most people arrive, stay for hours, and remember almost nothing.

Henrik Holmer researches and writes about lucid dreaming — the state in which someone becomes aware, inside a dream, that they are dreaming. Once that happens the dream can be looked at rather than simply endured, and that turns out to change quite a lot.

In this conversation he explains what is actually understood about it and what still isn't. What the brain is doing during REM sleep. Why reality checks and a dream journal are where almost everyone starts. Whether anyone can learn it, or whether some people never will.

He is at his most interesting on nightmares. His argument is that a recurring nightmare is not an enemy but a message being re-sent, and that becoming lucid inside one changes what you are able to do with it.

And then the questions with no settled answer — what dreams might be showing about the parts of a mind that stay quiet in daylight, and whether awareness continues while the body sleeps.