John Mayer's Song "Shadow Days" Is "Farewell Letter" to Jennifer Aniston
John Mayer is finally ready to let go of Jennifer Aniston -- in song. Although they split nearly three years ago, the 34-year-old singer (whose exes also include Jessica Simpson and Jennifer Love Hewitt ) penned his single "Shadow Days" (from the album Born and Raised ) with Aniston, 43, in mind. "Shadow Days is about Jen," a source tells Us Weekly . "It really took him a long time to get over her. He really loved her a lot." PHOTOS: John and Jen's intense romance Sings Mayer in the song: ""You find yourself alone. . . I found myself in pieces/ On my hotel floor/Hard times help me see/I'm a good man with a good heart/Had a tough time, got a rough start/And I finally learned to let it go." Explains the source: "He wrote the song as a farewell letter knowing [Jen] would hear it. Ultimately he's done a lot of self reflection though and it he realizes they weren't right for each other." PHOTOS: Jen's rocky romanc...