her/she

Last night Riley and I were in the kitchen and he started singing. At first I wasn't really paying attention but then I actually heard what he was saying and was amazed at how smart my little man is. He was singing a new country song that he has probably only heard a couple of times and although the words were not exactly right, they were close enough that I understood what song he was repeating. This is what he was singing... "her like to wear my shirt to bed, her like to ride around in my truck..." If you don't listen to country, you probably have no idea what song that is but he was pretty close to the words. It is actually  "she likes to wear my shirt to bed....". Sometimes he truly amazes me. Now why is it that he can remember a song he has only heard twice but he cant remember to clean his room, where he put his shoes or how to watch where his pee is actually going while using the bathroom!