If you have a day full of school and play, and
If you successfully fight off sleep during your mandatory “resting time,” and
If you pull out a looong piece of toilet paper to wind oh-so-carefully-and-tightly around the toilet paper holder*, and
If you shout a mean-spirited “NO!” to your mother as she puts you in Regular Time-out for the toilet paper offense, and
If your nasty “NO!” lands you in bed for More Serious Time-out, and
If you climb under the covers for a more comfortable punishment,
.
.
.
You might just fall asleep.
Sweaty, dirty, still fully clothed.
*He’s been warned.
These Walls 
Adults are like kids that way – our short tempers mean we’re tired and too stubborn to rest when we need it. (We’ve usually “evolved to sarcasm and cutting remarks in our advanced wisdom, but the concept is the same).