Annabeth nodded. "You're taking this awfully calmly."
Piper couldn't tell her why. She couldn't admit that this just confirmed some weird feelings she'd had for years, arguments she'd had with her father about why there were no photos of Mom in the house, and why Dad would never tell her exactly how or why her mom had left them. (4.8-10)
This passage doesn't entirely make sense; even if you thought there was something odd about your mom, it seems like you'd still be freaked out to learn she was a goddess. Maybe, though, Piper's calm because it's kind of cool to learn your absent parent is a goddess— something you wouldn't exactly expect, but might half hope for. It's like discovering you're really a secret princess. Maybe Piper saw a lot of Disney films.
I just saw my evil babysitter Tía Callida, Leo thought. She's got to be dead after all these years. And I can't go a day without remembering my mom in that machine shop fire. Don't talk to me about ghosts, doughboy. (5.30)
Tía Callida is Hera. In Greek mythology, she's Hephaestus's mother, so she'd be Leo's grandmother, not his aunt. Leo's being haunted by both his grandma and his mother, then. Is family a bunch of ghosts that just follows us through life?
"Sup, guys," Will said. "This is your new brother, Leo—um, what's your last name?"
"Valdez." Leo looked around at the other campers. We he really related to all of them? His cousins came from some big families, but he'd always just had his mom—until she died. (6.10-11)
Not only does Leo discover he's got superpowers, but he gets lots of siblings who all like to tinker with things too. Seems like a pretty good deal.
"Dad, just listen for once. Don't make me wait for you to ask your stupid three questions. I want to go to regular school. I want you to take me to parents' night, not Jane. Or homeschool me! I learned so much when we read about Greece together. We could do that all the time!" (9.43)
Tristan, Piper's dad, really does come off as kind of a jerk. Your kid begs you to spend more time with her and you just send her away? But then again, he's not throwing her from a height or literally biting her head off, so maybe by Greek god standards it's not so bad.
"Juno Moneta they once called me—Juno, the One Who Warns. I was guardian of the state, patron of Eternal Rome. I could not sit by while the descendents of my people were attacked." (25.18)
For Juno, family is a duty. That's different from most of the other gods we meet, for whom family seems like something you deal with haphazardly, out of affection and frustration.
"I'm not good with children," the god confessed. "Or people. Well, any organic life forms, really. I thought about speaking to you at your mom's funeral. Then again when you were in fifth grade…that science project you made, steam-powered chicken chucker. Very impressive." (29.63)
Hephaestus is a bit like Tristan McLean. For the record, we are not impressed by dads who can't show affection. Hugs and kind words are the best.
He watched Jason's face—looking more and more devastated as Thalia described their mom—and for once, Leo didn't feel jealous of his friend. Leo might have lost his mom. He might have had some hard times. But at least he remembered her. […] He felt bad for Jason, not having memories like that—not having anything to fall back on. (35.45)
Is it not having the memories that is painful here, or is it learning that his mom is a mess? Maybe it's both. Families—can't live with them, can't trade them in for a better model.
He could barely tolerate what she'd said about their mom. It was almost like Thalia had handed him a baby—a really loud, ugly baby—and said, Here, this is yours. Carry it. He didn't want to carry it. (37.4)
Families really are like that: you get them and then you have to carry them everywhere for the rest of your life. It's like every baby is handed a big, ugly baby when it is born.
She offered him the vial. "Take it. Maybe someday we'll be ready to talk about this again. When you're ready."
"When I'm ready," he murmured. "You make it sound like—like I'm the one growing up. I'm supposed to be the parent." He took the vial. His eyes glimmered with a small desperate hope. "I love you, Pipes." (46.29-30)
Tristan actually seems like a better dad when he's willing to let Piper take care of him. Remember that Zeus acts like an idiot and gets upset about his kids saving him. Being a good parent means letting your kids be the adults sometimes, maybe.
"This is where my mom took us when Jason was a child. She left him here, told me he was dead. He just disappeared." (48.27)
Thalia is talking about how her mom took them to the Wolf House and gave Jason to Hera. Of course, they then meet Hera at the Wolf House—and Thalia has a bitter, angry relationship with her, much like the relationship she had with her own mom. Hera's the evil step-mom in some ways, though the book suggests that evil step-moms aren't always entirely evil, even if they are kind of bossy.