Folded in half and still comfortable

The other day Colin went in for a nap but I heard him up kind of playing, kind of rustling around unsettled in his bed.  After about a half an hour it got pretty quiet and I poked my head in the door to see if he was actually sleeping or still rustling around.  And he was sleeping, but slumped over, folded right in half on top of his blanket with a few pacifers in his little hand!  How do kids do that?