I first noticed the 5 hour thing in college, when I perceived it as an asset. Study until the library closed at midnight, walk over the the pub for a drink with a buddy, in bed by 2:00 meant I could nab 5 hours before getting up at 7:00 for my first 8:00 class. Apparently I was somewhat functional, too, based on my grades.
After college I mostly forgot about it. 10 years later, enter babies and true sleep deprivation, then suddenly the 5 hour thing is a major player in getting through the day.
Now my kids are over 4 feet and the 8 hour snooze is no longer some longed for myth. Suddenly the 5 hour thing is a dreaded phenomenon. On a normal night, with sleep cycles being 1.5 hour loops, I'm out cold when the magic 5th hours comes. I sleep through the dog's squirrel dreams, kids grinding their teeth, hubby's snores. Occasionally, however, something happens at the 5 hour mark.
I've learned over the years that there is nothing I can do to trick my body back to sleep if awoken at the 5 hour mark. I've tried lying quietly in the warm dark for hours, snacks like turkey and cheese, thinking sleepy thoughts, reading a dull book, reading a funny book, melatonin, Tylenol PM, even Nyquil. No luck.
So last night when hubby had a leg cramp 5 hours after I'd nodded off, I lay in bed for an hour, then gave up and came downstairs. Maybe it is because I'm older, but I no longer perceive myself as functional. Especially at 4am. Rather than pull out the stack of work I need to do, I've been surfing the web for 4 hours now.
The kids are awake and Bill is making coffee. Maybe 5 cups is the cure to 5 hours?