Regardless of whether I can shift my affections to another - and the heart, as you observed, is a notoriously fickle beast - the question remains: should I?

I believe, Eragon, that you are full of love and that you are looking for one who will reciprocate your affection. No shame exists in that.

It is foolish to conjure up woe where none exists.

The future will be what it will, and fretting about it will only make your fears more likely to come true.

As he was about to leave, she said, "Murtagh." He paused and turned to regard her. She hesitated for a moment, then mustered her courage and said, "Why?" She though he understood her meaning: Why her? Why save her, and now why try to rescue her? She had guessed at the answer, but she wanted to hear him say it. He stared at her for the longest while, and then, in a low, hard voice, he said, "You know why.

It’s better to be sworn to an honest fool than to a lying scholar

Because you can't argue with all the fools in the world. It's easier to let them have their way, then trick them when they're not paying attention.