Can't sleep? Here's an article from Health.com that explains everything you'd want to know about the 11 types of insomnia (Yes, there are 11! If one didn't get you, the others will.)
One of the weirdest is paradoxical insomnia, where people complain of sleeplessness, but actually slept through the night:
Paradoxical insomnia is a complaint of severe insomnia. It occurs without objective evidence of any sleep disturbance. Daytime effects vary in severity, but they tend to be far less severe than one would expect given the expressed sleep complaints.
People with this disorder often report little or no sleep for one or more nights. They also describe having an intense awareness of the external environment or internal processes consistent with being awake. This awareness suggests a state of hyperarousal. A key feature is an overestimation of the time it takes them to fall asleep. They also underestimate their total sleep time.
Another feature is that the degree of sleep deprivation reported seems improbable. Their level of daytime functioning is likely to be only moderately impaired. Objective findings of fairly normal sleep duration and quality tend to result from an overnight sleep study. These findings are much different from their perception of poor quality sleep.