“I don't feel that way anymore," Nico muttered. "I mean… I gave up on Percy. I was young and impressionable, and I-I don't…”

“I'm way hot," he muttered. "But I don't feel sick. Just — way hot."
Fang”

“I (Percy) set Nico on guard duty with Beckendorf and the Stoll brothers, figuring he'd be safely out of the way.
…
"What's happening?" Nico demanded, trying to climb up next to me.”

“I don't feel the need to explain my actions to her. I don't clarify, I don't doubt, I don't worry. I don't tell her everything, not anymore, but I tell her more than anyone else, by far. I tell her as much as I can.”

“It's cold and it's mean spirited and I don't like it here anymore.”

“Aphrodite: Pfft. That's not the point. Follow your heart.
Percy: But… I don't know where it's going. My heart, I mean.”

“She said, 'Believe it or not, I used to be idealistic.' I asked her what 'idealistic' meant. 'It means you live by what you think is right.' 'You don't do that anymore?' 'There are questions I don't ask anymore.”

“This is why I forgive, but I don't forget. When you forget someone, the forgiveness doesn't mean anything anymore.”

“I don't think of death in a romantic way anymore. (L'Express newspaper 2000)”

“A year ago, I turned the final page of The Book of the Dead. I don't feel young any more.”