Because they can do stuff like this... fall sleep... while... slowly falling... off a couch... scrunched up in his shirt...
This is our Son #2, and he has a history of falling asleep on chairs, behind doors, curled up in a tiny ball somewhere in the house... and we find him like 3 days later.
Ever since he was a little baby, he would run and run and run and run until he just stopped and fell right over asleep.
And you look at 'em at that tender age and think, oh they will out grow it.
Well, sometimes they don't. :-) I'm sure he fell asleep there playing.
And thats why kids are awesome.
Oh, anyway, I'm pretty sure if our Son #2 was a super hero, his super power would be sleeping... kinda like his father. :-)
I wonder what our other children's Super Hero Powers would be?