Contiguous Sleep Cycles

My upper respiratory infection has been trending to resolution with symptomatic intervention.  Cough drops, some therapeutic, some more tasty, have done what they should.  Fluticasone may be taking effect  on the rhinitis, or perhaps I am just recovering.  NyQuil has proven the most valuable, not so much because of any anti-tussive or sympathomimetic properties but because it enables me to transition from one sleep cycle to the next seamlessly.  This rarely happens spontaneously nowadays.  My iTouch buzz even woke me this morning from a more significant part of the sleep cycle.

Despite some effort to understand sleep and sleep hygiene better as it increasingly affects me, the role of transitions from one cycle to the next seems ill-defined.  Nature did not intend it to be wakefulness, though perhaps a periodic scan for predators each night might have evolutionary purpose.  Probably not as much purpose as full alertness when daylight arrives.  Even if mediated by exogenous chemicals, I appreciate the more continuous nightly snooze, even if I don't understand its mechanism or how the NyQuil components compensated.  Though, for sure, it is not a suitable chronic sleep aid.