By then Esthappen and Rahel had learned that the world had other ways of breaking men. They were already familiar with the smell. Sicksweet. Like old roses on a breeze. (1.39)
The loss of innocence is central to the plot of the novel, and we see a hint of it here. Carefree children don't know anything about how the world "breaks men," but kids who have been through a major ordeal do.
When they left the police station Ammu was crying, so Estha and Rahel didn't ask her what veshya meant. Or, for that matter, illegitimate. It was the first time they'd seen their mother cry. (1.58)
Here we see a mingling of innocence and the loss of it. Estha and Rahel don't know exactly what these hurtful words hurled at Ammu mean (veshya means prostitute), which shows that they still live with some sense of innocence. Still, the first time you see your mom cry is a big deal and can change the way you view the world. You realize your parents are fragile just like everyone else.
When the twins asked what cuff-links were for – "To link cuffs together," Ammu told them – they were thrilled by this morsel of logic in what had so far seemed an illogical language. Cuff + link = cuff-link. This, to them, rivaled the precision and logic of mathematics. (2.87)
The book is full of great tidbits like these, where we get to see the world through the eyes of a child. We watch as they start to understand the world, in serious ways and in silly ones like this.
"Bow," [Estha] said, and smiled, because when he was younger he had been under the impression that you had to say "Bow" when you bowed. That you had to say it to do it. (4.23)
Here we see Estha holding on to a bit of his childlike innocence. He smiles when he thinks back to the way he viewed the world when he was still innocent. Even though he now knows that you don't have to say "bow" when you perform the action, he does it anyway – and the little kid who once invented that rule lives on in him.
There was a voice from outside the picture. It was clear and true, cutting through the fan-whirring, peanut-crunching darkness. There was a nun in the audience. Heads twisted around like bottle caps. Black-haired backs of heads became faces with mouths and mustaches. Hissing mouths with teeth like sharks. Many of them. Like stickers on a card.
"Shhhh!" they said together. It was Estha who was singing. A nun with a puff. An Elvis Pelvis Nun. He couldn't help it. (4.53-54).
We can almost hear Estha's pure, true voice carrying over the soundtrack of The Sound of Music. He can't help being overtaken by the music he loves so much. This is one of the last moments of sheer joy that Estha will ever experience, and we can't help but feel a little heartwarmed by it. The simplicity and innocence here makes the molestation that happens just moments later seem all the more vile and terrible.
"Where d'you think people are sent to Jolly Well Behave?" Estha asked Rahel in a whisper.
"To the government," Rahel whispered back, because she knew. (6.187-188)
This exchange gives us more insight into the way Estha and Rahel think the world of grown-ups works. (To them, "the government" is some scary, physical place.) This moment mixes equal parts wonder and fear to give us a glimpse into Estha and Rahel's incomplete view of the world.
As Estha stirred the thick jam he thought Two Thoughts, and the Two Thoughts he thought were these:
(a) Anything can happen to anyone. and (b) It's best to be prepared.
Having thought these thoughts, Estha Alone was happy with his bit of wisdom. (10.27-31)
Estha thinks his Two Thoughts in response to the fear that the Orangedrink Lemondrink Man, who molested him earlier that day, will come find him in Ayemenem. Estha's experience of sexual abuse jumpstarts his loss of innocence. We see him taking on a new view of the world in this scene: he goes from being naïve to taking responsibility for his own survival.
"If you're happy in a dream, Ammu, does that count?" Estha asked.
"Does what count?"
"The happiness-does it count?"
She knew exactly what he meant, her son with his spoiled puff.
Because the truth is, that only what counts counts.
The simple, unswerving wisdom of children. (11.46-51)
Estha shows Ammu (and us) that kids might be simple in a lot of ways, and maybe sometimes they sound a little silly, but sometimes their simplicity is profound. This moment stays with Ammu and resurfaces later in the book.
Dead fish floated up in Estha. One of the policemen prodded Velutha with his foot. There was no response. Inspector Thomas Mathew squatted on his haunches and raked his jeep key across the sole of Velutha's foot. Swollen eyes opened. Wandered. Then focused through a film of blood on a beloved child. Estha imagined that something in him smiled. Not his mouth, but some other unhurt part of him. His elbow perhaps. Or shoulder.
The inspector asked his question. Estha's mouth said Yes.
Childhood tiptoed out.
Silence slid in like a bolt. (19.80-83)
This is a moment that will stay with Estha for the rest of his life. (We learn about it all the way back in Chapter 1 when we meet Estha as an adult.) The thing that grabs you by the shoulders and shakes you is the way it so quickly and jarringly changes Estha's experience of the world. The second he condemns Velutha, he ceases to be a child. This moment signifies the end of Estha's innocence and introduces us to the Estha we know as an adult: guilt-ridden, silent, and traumatized.
It took the twins years to understand Ammu's part in what had happened. At Sophie Mol's funeral and in the days before Estha was Returned, they saw her swollen eyes, and with the self-centeredness of children, held themselves wholly culpable for her grief. (20.15)
Here, innocence can also be seen as a lack of awareness. Estha and Rahel don't know what's been going on between Velutha and Ammu, and they assume their version of events is the only version.