Is "microsleep" real or it's just a joke that people do?

It's real: Microsleep is a sudden transition from wakefulness to sleep that can be dangerous in many situations (for example, when driving or operating heavy machinery). It usually occurs due to sleep deprivation, though normal non-sleep deprived individuals can also experience microsleep. See a neurology or pulmonary sleep specialist to be evaluated. http://www.sleepdex.org/microsleep.htm