Uh-oh. Thud.

So last night when she's supposed to be "sleeping like a champ", Elsa took her socks off and threw them and her penguin on the floor. Thud. It was the first time she even tried to climb out of her crib. And she made it up and over with a crash landing and no tears, just waiting for someone to come in and help her and her penguin out of a jam. We got her settled back in and ten minutes later she was up and over the wall again.

She's been pulling out all the stops at bedtime: "kiss Rody", "more cuddles", "another book". Is there something that happens around 21 months that makes the little ones put up the fight at bedtime?