Things said and done then must be, as you said, the only memory of good times.. But saying this I also think that by looking at the ring she can only be reminded of how her life could have been. She could only wish for it so the ring becomes a pain
how the fate becomes to laugh in your face! remember when she try hard to took off the ring,she said:i don't want anything to remember you! and now,the ring is her only memory from those happy days!