There’s a well-documented phenomenon in sleep science: people systematically misjudge how well they slept. Some wake up convinced they didn’t close their eyes all night, even though recordings show hours of real sleep – a phenomenon called “paradoxical insomnia.”
The opposite happens too: people who sleep shallowly, with frequent awakenings they don’t remember in the morning, are convinced they had an excellent night. The brain simply doesn’t reliably record transitions between sleep stages, especially the short ones.
That’s why the subjective feeling – “I feel rested” or not – is a real but incomplete clue. Sleep quality has components you don’t feel directly: deep sleep duration, bedtime regularity, number of awakenings.
A structured score, weighing several factors at once, can sometimes paint a rather different picture than your first impression in the morning.
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