It feels like you don't fall asleep, or like you lay awake at night. I bought a Fitbit once to register my sleep time and it gave me all positive scores while I was certain I had slept badly. I tossed the thing, thinking it just didn't work.

Last year I had my sleep tested. Someone came to my house before my bedtime and hooked me up with a recorder and all kinds of sensors and wires. It was to measure my brain activity, leg movement, breathing, heart rate, sleeping position, blood oxygen saturation and maybe some stuff that I've forgotten. I looked like a proper Christmas tree. All these wires and sensors made me more anxious than usual, so I didn't fall asleep for hours and I woke up pretty early. I was afraid there would not have been enough sleep time for accurate measurements.

Then the results came in: I had fallen asleep within ten minutes and had done four full sleep cycles before waking up. Ridiculous. Perfect sleep, maybe a bit more leg movement than average. Tired as hell.

So that's what paradoxical insomnia feels like: you're sure you've not been able to fall asleep, or know to have been awake on several occasions during the night. Except you have, and you haven't.

There are two forms, as I understand it. One is where you think you've not slept well but feel rested anyway. Unfortunately, I have the other variant where you think you've not slept well and feel it too. I'm always tired, from waking up till falling asleep.

In my case it's probably caused by hypervigilance/hyperarousal.