Final answer:
Charlie experienced transience, a memory fading effect, causing him to forget the last few notes of a song while performing.
Step-by-step explanation:
Charlie forgot the last few notes of "Twinkle, Twinkle, Little Star" when playing in front of his parents due to a phenomenon called transience, which is the tendency for memories to fade over time. This is one of the forgetting errors where information that isn't used regularly becomes harder to retrieve. When learning to play the piano, mnemonic devices like "Every good boy does fine" can help remember notes on the treble clef, improving acoustic encoding which is the process of encoding sound patterns that can enhance our ability to remember information. Practice and rehearsal are critical components of memorization, and in Charlie's case, the pressure of performance or a lack of repetition could have contributed to his difficulty in recalling the last notes.