He wanted no sadness attached to his childhood; he loved its memories; any day of it he remembered now seemed flooded by a still, brilliant sunlight. It seemed to him as if a few rays reached into his present; not rays, more like pinpoint spotlights that gave an occasional moment's glitter to his job, to his lonely apartment, to the quiet, scrupulous progression of his existence. (184.108.40.206)
Eddie loves his childhood memories, but it's important to note that his happy childhood is largely separate from his adult life, existing as nothing more than "pinpoints" of light. Eddie seems to have lost his happiness and can only access it in his memories.
After a while, he realized that he was thinking of his past, as if certain days of it were spread before him, demanding to be seen again. He did not want to look at them; he despised memories as a pointless indulgence. But then he understood that he thought of them tonight in honor of that piece of metal in his pocket. Then he permitted himself to look. (220.127.116.11)
It's interesting that Hank refuses to look at his past usually while Eddie cherishes his. The reason for Hank's refusal might have something to do with his guilt and his internal struggle over value systems. Hank would rather not recall struggling and being unhappy perhaps.
She fought. She recovered. Years helped her to reach the day when she could face her memories indifferently, then the day when she felt no necessity to face them. It was finished and of no concern to her any longer. (18.104.22.1680)
Dagny battles with her past head-on until it no longer controls her or causes her pain. Though Dagny eventually puts the past aside, she doesn't just ignore it from the start.
"Francisco...if he could live through that night what right have I to complain? What does it matter, how I feel just now? He built that bridge. I have to hold it for him. I can't let it go.... I feel almost as if he'd know it, if I let that happen, he'd know it that night when he was alone over the river. (22.214.171.124)
Dagny draws on the memory of her heroic ancestor, Nat Taggart, to psych herself up for a fight. She feels like her failure would somehow reach back in time and impact Nat, as if the present could alter the past.
Now, looking from the memory of the girl on the flatcar to the Gift Certificate lying on his desk, he felt as if the two met in a single shock, fusing all the days and doubts he had lived between them, and by the glare of that explosion, in a moment's vision of a final sum, he saw the answer to all his questions. (126.96.36.199)
After his epiphany, Hank's past and present fuse together. He suddenly understands his past and everything that has led him to this moment, when he gains a fuller understanding of himself.
When she opened her eyes, she saw sunlight, green leaves and a man's face. She thought: I know what this is. This was the world as she had expected to see it at sixteen – and now she had reached it – and it seemed so simple, so unastonishing, that the thing she felt was like a blessing pronounced upon the universe by means of three words: But of course. (188.8.131.52)
Atlantis is all about recapturing the joy of childhood, so it's fitting that it matches the vision of the world Dagny had as a teenager. It's interesting that she says "but of course" here, implying that the visions of her sixteen-year-old self were destined to be true.
"We're going to have security – for the first time in centuries – for the first time since the beginning of the industrial revolution!"
"Well, this, I guess," said Fred Kinnan, "is the anti-industrial revolution." (184.108.40.206-6)
Kinnan's snotty comment connects to the theme of historical backslide that often crops up in regard to the looters and their fear-inspired policies.
"If you weren't, you'd know that it's not this valley, but the view of life held by men in the outer world that is a prehistorical mirage." (220.127.116.11)
Ragnar again demonstrates the "opposite day" of the looters and their worldview by telling Dagny that the seemingly magical and "prehistoric" Atlantis should be present reality.
He rose, he drew her to her feet – and when his arms closed about her, their kiss was the summation of their past, its end and their seal of acceptance. (18.104.22.168)
By reconciling, Francisco and Dagny are able to both recapture their past and conclude that phase of their relationship.
Then, still holding the recaptured sensation of what she had felt for him in the past, she grasped a quality that had always been part of it, now suddenly clear to her for the first time:...what she had felt for Francisco had always been a celebration of her future.... (22.214.171.124)
Dagny links up her past, present, and future here by recalling how her past with Francisco was a celebration of their childhood dreams for the future, which they've now achieved. It seems that for a person to be truly whole, her past, present, and future need to be connected. Hank discovers this when he signs the Gift Certificate.
". . . this is how I've watched you for ten years...from the ground under your feet...ten years of nights spent waiting to catch a glimpse of you here, on the platform, when you boarded a train . . ." (126.96.36.199)
After starting a relationship with Dagny, John seems almost compelled to run through their history as a way of getting it out of his system and letting them start in the present. His speaking style here is very unusual for him, too, breathless and full of stops and starts and incomplete sentences.
She knew what Nat Taggart had felt at his start and why now, for the first time, she was following him in full loyalty; the confident sense of facing a void and of knowing that one has a continent to build.
She felt the whole struggle of her past rising before her and dropping away, leaving her here, on the height of this moment. (188.8.131.52-35)
Once again, the theme of the present erasing the pain of the past emerges. It's interesting that Dagny is able to let go of her past pain by identifying with a figure of the past, Nat Taggart.