Spontaneous Sleepers

Since becoming a mom I have spent countless nights being awakened hour after hour nursing a baby, soothing a scared toddler or convincing a child that 4am is not an appropriate time to wake up.  Even on the days that follow the very worst of those nights I can't imagine ever being tired enough that I could fall asleep like this...  

or this...

Additionally I can't remember the last time that I woke up with this look on my face wondering where I was and how I got there.