Short-term memory

Daryl will call his mum a few times during the day to make sure that things are going well with Randall. Most of the times, he'll come back with little funny stories about what Randall did. For instance, just this afternoon, mil went into the storeroom to get hangers. Seeing that she was inside, Randall closed the door, and went to play. After a while, he realised that his "mah-mah" was nowhere to be found. He ran all around the house looking for her while shouting anxiously, "Mah-mah! Ni zai na li (where are you)? Ni zai na li?" It took him awhile to recall that he locked his mah-mah in the storeroom. He quickly rushed to open the storeroom door and said, "Mah-mah, ni chu lai (you come out)!" Haha... I think they don't have much memory capacity at this age, do they?