Meaning of "You're So Yesterday" by Marvelous 3

The lyrics of "You're So Yesterday" by Marvelous 3 depict a tale of a toxic relationship that has come to an end. The singer describes meeting someone who seemed cool at first but turned out to be manipulative and unappreciative. The imagery of washing away the memories of this person, symbolized by washing their blonde hairs down the drain, indicates a desire to move on and cleanse oneself from the negative influence this person had. The reference to New Year's Day represents a new beginning and a resolution to leave this destructive relationship behind. The singer acknowledges the hurt caused by this person but ultimately decides to let go and move forward. The repeated refrain of "you're so yesterday" emphasizes the singer's determination to leave the past behind and focus on the future.