Yeah the one "that got away" will always be the one who never put a foot wrong or would never do something offensive. They also never age, never argue, never really leave.. the classic widow-problem.
However, dwelling on a "lost chance" be it the partner one never got to keep, the job, one was "forced to give up", the many regrets one might have over the course of a life is not very healthy.
If anything it keeps you from enjoying life.
Was Mragarets endless almost pathetic desperate quest for "more life - more fun - more more" a result of her love disappointment or was it the other way around? Did she set herself up for failure with Townsend? Did she choose him, knowing this relationship would never be allowed and the endless speculation and pity would grant her a unique place in the limelight?