Quote 1
"Did you win?"
Luce laughed a sad, self-effacing laugh and shook her head. "Far from it."
Daniel pursed his lips. "But you were always…"
"I was always what?"
"I mean, you look like you might be a good swimmer," He shrugged. "That's all." (6.79-83)
This quote's more about an actual loss, rather than an emotional one. The important note here isn't about Luce winning or losing the race, but about Daniel's expectation that she would win. Just another moment when he gives away something that maybe indicates he knows more about her than he's letting on.
Quote 2
"I know cam gave you that gold necklace, too," Daniel said.
Luce hadn't thought about that since Cam had forced it onto her at the bar. She couldn't believe that was only yesterday. The thought of wearing it made her feel sick. She didn't even know where the necklace was—and she didn't want to. (20.72-73)
Although it seems a little anticlimactic to go from talking about the end of the world to talking about a missing necklace, this detail is important. Luce's attention to detail dwindles when she stops caring about things, and the fact that she lost Cam's necklace solidifies that any feelings she had for him really were entirely superficial. She isn't ever going back. It's now 100% Luniel. Or…Danuce?
Quote 3
"Warm milk with a spoonful of treacle," he murmured sadly, his back still to her. Then he added sadly, "It helps you sleep." (Prologue. 17)
How does Daniel know this? Oh, yeah—he remembers it from one (or several) of Luce's past lives. Does Luce pick up on this? Nah. She wouldn't be a YA heroine if she did.