The lyrics of the song 'Nothing Compares 2 U' by Sinead O'Connor express the pain of losing a loved one and the inability to move on. The singer compares her life before and after the breakup, and nothing seems to compare to the love she had. The song talks about the loneliness and the tears that come with the loss of a loved one. The singer also mentions the advice given by a doctor to have fun, but she believes that nothing can replace the love she had.