The feeling of being both exhausted and wired when going to bed (the 'tired but wired' phenomenon) is not a lack of fatigue, but the result of a state of hyperarousal where the body, mind, and emotions remain stuck in alert mode.

noli's read

This model of hyperarousal is the major scientific framework for explaining sleep difficulties, widely validated by research. A literature review conducted by researcher Dieter Riemann (2010) confirms that this state involves an activation of the nervous system and stress hormones both day and night. This persistent arousal manifests as accelerated brain activity and a tendency toward mental rumination, two aspects documented by multiple observational and neuroimaging studies. However, a theoretical analysis published in 2023 qualifies the evidence regarding certain physical markers, such as heart rate variations, which remain less consistent from one study to another. Finally, Walker's idea that one is 'too good at staying awake' is a charitable reformulation that is ideal for well-being, even if the phenomenon biologically stems from excessive stress reactivity rather than voluntary success.

the sources

No named source held this one up — that absence is part of the verdict.