Adan has been trying to recall the name of the musical artist who released the song that was number one when he was 14. Adnan feels somewhat frustrated because he is certain he knows the artist's name, but he just can't seem to recall it at this moment. Adnan is experiencing something referred to as LETHOLOGICA.
LETHOLOGICA is also known as “tip of the tongue”; this is where one is unable to remember a particular word or name for something or someone.