Sometimes someone says something really small and it fits right into this empty place in your heart.

And this shows that sometimes people want to be stupid and they do not want to know the truth.
And it shows that something called Occam's razor is true. And Occam's razor is not a razor that men shave with but a Law, and it says

Entia non sunt multiplicanda praeter necessitatem.

Which is Latin and it means

No more things should be presumed to exist than are absolutely necessary.

Which means that a murder victim is usually killed by someone known to them and fairies are made out of paper and you can't talk to someone who is dead.

Excerpt from The Curious Incident of The Dog in The Night-Time written by Mark Haddon.