Here he is with his Lion King puzzle--he put it together all by himself! At the beginning, he shooed me away and announced he wanted to do it all by himself. During the process, half of the time he was singing (see video below) and the other half he was urging me to help him: "It's harder!" And I kept encouraging him on to do it by himself.
And, ta-da! Look at that proud smile!
Here is a little video of Nick multitasking, puzzling and singing a little ditty he made up.