"You're entirely bonkers. But I'll tell you a secret: All the best people are."  - Alice in Wonderland

"When you tend a rose, my lad, a thistle cannot grow." - the Secret Garden

"Happiness can be found in the darkest of times, when one only remembers to turn on the light." - Harry Potter

"But if hero isn't willing to lose everything for a greater cause, is that person really a hero?"  - The Tower of Nero

Just some of my favorites! :D 

"Adam Parrish was lonesome.

"There is no good word for the opposite of lonesome. One might be tempted to suggest togetherness or contentment, but the fact that these two other words bear definitions unrelated to each other perfectly displays why lonesome cannot be properly mirrored. It does not mean solitude, nor alone, nor lonely, although lonesome can contain all of those words in itself.

"Lonesome means a state of being apart. Of being other. Alone-some.

"Adam was not always alone, but he was always lonesome." 

-- Blue Lily, Lily Blue by Maggie Stiefvater

"ah, that's infinetely better."

-Darkstalker, Wings of Fire: Talons of Power

"we the dragons of the sky! we can fly and fly and fly, we go up so super high! we the dragons of the sky!"

-Cliff, Wings of Fire: Escaping Peril

"MY brain words! words of my head!!"

-Luna, Wings of Fire: Flames of Hope 

"dose were MY CASHOOS!"

-Bumblebee, Wings of Fire: Flames of Hope (epilogue)

"that's everyone! I mean, except for Turtle, but he'll come wheezing up soon, don't worry."

-Tsunami, Wings of Fire: the Dangerous Gift

"you didn't prepare actual fireworks, though, did you?" Clearsight said.

"noooo..." Darkstalker replied. "not if you... hate fireworks?"

-Wings of Fire Legends: Darkstalker 

"A philosopher is one who attempts to capture the truths of the universe so precisely that they become too confusing to understand. A novelist is one who attempts to capture the truths of the universe in such a roundabout way that they become obvious to anyone who reads them."

"And a witch?"

"A witch kills the dead."

-- Cinders & Sparrows by Stefan Bachmann

"The more I got to know people, the more I realized we were all just a bunch of frightened idiots walking around in the dark, bumping into each other and panicking for no reason at all.

"So I started turning on a light."

-- A Very Large Expanse of Sea, by Tahereh Mafi 

"What's the best way to steal a man's wallet?"

"Knife to the throat?" asked Inej.

"Gun to the back?" said Jesper.

"Poison in his cup?" suggested Nina.

"You're all horrible," said Matthias. 

-- Six of Crows, by Leigh Bardugo 

'The end of the world started when a peguses landed on the hood of my car.' 

Percy Jackson and the Olympians book 5 The last olympian 

"It's not natural for women to fight."

"It's not natural for someone to be as stupid as he is tall, yet there you stand."

— Leigh Bardugo, Six of Crows

"Yes, of course duct tape works in a near-vacuum. Duct tape works anywhere. Duct tape is magic and should be worshipped." — Andy Weir, The Martian

"Do not second-guess the sack of flour. The sack of flour is wise beyone her years." — Leigh Bardugo, Rule of Wolves 

"I was a very odd little girl."

-- Skyward, by Brandon Sanderson

"You'll just have to make the best of it down here," he said to Richard, "in the sewers and the magic and the dark."

-- Neverwhere, by Neil Gaiman 

"It was all very well going on about pure logic and how the universe was ruled by logic and the harmony of numbers, but the plain fact of the matter was that the Disc was manifestly traversing space on the back of a giant turtle and the gods had a habit of going around to atheists' houses and smashing their windows."

-- The Color of Magic, by Terry Pratchett 

"My words are unerring tools of destruction, and I have come unequipped with the ability to disarm them." -- The Raven Boys, by Maggie Stiefvater

"I am not ruined. I am ruination." Genya Safin, from the Shadow and Bone series (can't remember which book)