The other night (when Noah and I were both sick) Lincoln came bouncing down the stairs, pleased as punch,to announce that he could get out of the pack 'n play. He had slept late during his nap, so we decided to let him stay up a little bit before we re-attempted. Not the best strategy, perhaps, but we were sick.
He sat down with some yellow duplos and started working. (forgive the broomball stick and vaccum cord in the background. The vaccum cord shows some good intention...but a broomball stick indoors?! That does not show good intuition...)
He would stack them up, but if it would break in the process he would take all of his work completely apart and start over. Even if he was just one Duplo away from completion, and the tower just split in two, he would still pull everything apart and start over.