Truth is scattered. You don't find it all in one spot; as you move along through your life you find it in pieces, here and there. Especially personal truth, the seemingly-small things you need to know in order to push forward with calmness and dignity.
I found a little piece of personal truth I have been searching for for years in a book that I read years ago, before I needed that truth. My memory of C. S. Lewis's novel Till We Have Faces was vague. 
I read it when I was working on my English degree, not for a class but because a friend I made at school read it for one of her classes, wrote an essay about it, and asked me to proofread what she'd written. Her essay made the novel impossible for me to resist.
It is a perfectly Amy sort of book: a retelling of the Cupid and Psyche myth. Literary giants revisiting old stories is one of my favorite sort of books. You know the tale: Cupid, who is Venus's son, falls in love with the beautiful mortal Psyche when his mother sends him to make her fall in love with the basest of men. Instead, Cupid sends the west wind to scoop up Psyche and bring her to his palace, where he loves her nightly. Because his mother still despises Psyche (as men tend to forget about worshipping Venus when Psyche is near), this loving must be done in secret, in the dark. All is well until Psyche's two jealous sisters visit her in her godly palace. They convince her to sneak a lamp into the palace, and to look at her mysterious lover in secret. This, of course, doesn't turn out well for Psyche, who is cast away from Cupid's presence and sent to do a series of impossible tasks by Venus. Her beauty rescues her, as it inspires people, ants, the eagles of the gods to help her, and at last she is reunited with Cupid and made a goddess.
Lewis retells the myth through the perspective of Orual, Psyche's sister. He makes another crucial change: when Orual visits Psyche, she cannot see the palace. This utterly changes the scope of the story, because Orual, Psyche's sister, must work out her experiences by her faith rather than knowledge. The tale becomes not one of jealousy, as the myth goes---although jealousy plays a part---but of seeing oneself truly, and understanding why we make the choices we do.
In the end, Orual takes her complaint to the Gods. This is the "speech which has lain at the center of [her] soul for years, which [she] has, all that time, idiot-like, been saying over and over." Her complaint is that the Gods made it so she couldn't know what she was doing when she convinced Psyche to peek at the God; as she goes through the process of putting this into words for the Gods, she realizes that, in her heart, she did know. She sees her own imperfect motivations and sees what fed her actions (loneliness, fear, the desire to possess Psyche).
My complaint is nothing like Orual's. And yet, perhaps the motivations behind it are the same. What I do know is that I continue to have that speech in me, right at the center of my soul, that I continue to say. It is based on the things that have happened and my lack of understanding at why they happened that way; wouldn't a God who loved me, I think in my deepest self, have helped it happen another? Wouldn't a God who loved me let me have the sincere desires of my heart? That is the idiot-like speech that circles, over and over in endless permutations, in my heart.
It is what Orual says next that is my piece of wisdom. "I saw well why the gods do not speak to us openly," she writes. Here is why the whirlpool of unanswered anguish continues. "Till that word can be dug out of us, why should they hear the babble that we think we mean?" Until, in other words, we can see ourselves—until we know that word—we cannot understand even what the right question is. And, I think, once we see ourselves, the question might not even exist anymore. "The complaint," Orual realizes—I realize, "the complaint was the answer. To have heard myself making it was to be answered."
As I read this section of the book—the last ten pages or so—I was, literally, sobbing. That ugly cry that releases stones long held. The wisdom it gave me wasn't an answer to my circle of questions. It wasn't my complaint answered. It was the deep, abiding knowledge that, however, my speech is heard. When Orual was in the very moment of deciding how she would treat Psyche, she has the knowledge within her of what she should do. She knows. That was the rest of the personal truth I got from the book: that while I cannot yet see which word is the word, one of them is. I have the answers within me. When I am finally able to see myself—an experience Orual doesn't arrive at until she is very old—I will also be able to know the truth.
There are many other essays to be written about this book, works on faith and on beauty and on knowledge. I still have other words I could say. But on this reading, this is what matters, this nearly-unsayable knowledge that has brought me great peace.