Baby growth confusion

Footy Faux Pas! Baby Doug Stretches his PJs, Thinks He's Grown in Today's Hilarious Dog Eat Doug Comic!

Funny Comic Strips: Baby Doug plays with his pajama feet.
Funny Comic Strips: Baby Doug yanks his pajama footy up to his head.
Funny Comic Strip: Baby Doug releases the footy but it stays stretched out and flops on the floor.
Funny Comic Strip: Puppy Sophie walks up to Doug and says, "Don't worry too much. Your other foot will catch up in eighteen years or so."

Grow, Grow, Footie! Baby Doug's Pajama Panic Stretches the Laughs in Dog Eat Doug!

I know they sell these pajamas for adults. I assume they’re comfortable but I also assume you might bust your butt on the kitchen tiles like when you were a kid. Those footy coveries can get slick.