Carry A Torch For Meaning

(idiomatic) To love or to be romantically infatuated with, especially when such feelings are not reciprocated.

Example: 1955, "Books: Mixed Fiction" (review of The Twelve Pictures by Edith Simon), Time, 6 June:
  Brunhilde, a kind of earth-mother goddess, carries a torch for her lost love.
2006, Jeannette Walls, "Are Simpson and Lachey still in love?," msnbc.com, 20 April:
  Lachey, for his part, seems to still carry a torch for his estranged wife.