There is always someone in your life that you will never forget. Maybe you just passed by, maybe you met by chance, maybe as the song says, "Just because I looked at you one more time in the crowd, I can never forget your face again", or maybe the protagonist in the article is a former classmate...
No matter which one it is, if you had the opportunity to see this person again, what would you want to say to this person...
Wong Kar-wai said that all encounters in the world are reunions after a long absence.