Hogfather by Terry Pratchett:

„

right," said Susan. "I'm not stupid. You're saying humans need... fantasies to make life bearable."

REALLY? AS IF IT WAS SOME KIND OF PINK PILL? NO. HUMANS NEED FANTASY TO BE HUMAN. TO BE THE PLACE WHERE THE FALLING ANGEL MEETS THE RISING APE.

"Tooth fairies? Hogfathers? Little—"

YES. AS PRACTICE. YOU HAVE TO START OUT LEARNING TO BELIEVE THE LITTLE LIES.

"So we can believe the big ones?"

YES. JUSTICE. MERCY. DUTY. THAT SORT OF THING.

"They're not the same at all!"

YOU THINK SO? THEN TAKE THE UNIVERSE AND GRIND IT DOWN TO THE FINEST POWDER AND SIEVE IT THROUGH THE FINEST SIEVE AND THEN SHOW ME ONE ATOM OF JUSTICE, ONE MOLECULE OF MERCY. AND YET—Death waved a hand. AND YET YOU ACT AS IF THERE IS SOME IDEAL ORDER IN THE WORLD, AS IF THERE IS SOME...SOME RIGHTNESS IN THE UNIVERSE BY WHICH IT MAY BE JUDGED.

"Yes, but people have got to believe that, or what's the point—"

MY POINT EXACTLY

„

One of the better reasons for religion is that comprehending the uncaring vastness of the universe risks breaking our minds

If getting what we want makes us happy
And what we want is to be sad

Then are we happy or sad?

I am 14 and this is deep.

Being broke and hungry doesn’t make anyone happy really.

That's one way of dealing with running out of hot water

I mean, everything is part of the universe, including our brains and the chemicals inside them that manifest experientially as happiness and sadness. You can certainly take more control over what causes those emotions in you, but you're still part of the universe.