I've got the whole world in my hands

For a while Sam was in a phase of serial processing. He could only hold one thing in both hands at one time. And even if one hand was free, that didn't mean it could hold something. If he was holding a toy car but wanted to take the straw Dave was offering him and throw it on the floor, first he had to give Dave his car, then take the straw, then throw it on the floor, then take his car back. He couldn't keep the car in one hand and with the other take the straw and throw it on the floor. No...that would be two things at once.

Now Sam seems to be in a phase of fitting everything he can into one hand. As I put away laundry he pulls out all the socks and tries to carry as many as possible in one hand (and gets immense satisfaction out of it when he carries many). Or he walks around carrying various wooden puzzle pieces in one hand, or takes all his apple pieces and holds them in one hand while he eats one by one with the other hand. It's rather comical...