In this one, many think that the person who "sailed away" from her life, the "one true love" was indeed, Mac Miller.
"I ain't lookin' for my one true love / Yeah, that ship sailed away"
Even after their break-up, Ariana remained positive that the two of them would maintain some kind of relationship before he passed away. In her song, "In My Head" she mentions how Mac was "the one," too.