Prejudice towards the letters

Cailin and I have been working on the alphabet lately. She has been working on it for about two weeks and has gone from not knowing what a letter is, to being able to sing the ABC song. She can tell you "A says AAAhhh, B says buh, and P says popcorn". It makes me smile. She sang the ABC song last night perfectly. She didn't slur the LMNOP like a lot of people do! Today, she was singing over and over on the way to MOPS, but she was leaving off WXYZ. When I tried to remind her of those letters, she would cut me off and tell me she was singing by herself. I asked her what happend to the last 4 letters. Her reply, "I don't like them anymore". I guess you can skip the letters you don't like anymore.