Truth is always strange, stranger than fiction.

It's no wonder that truth is stranger than fiction. Fiction has to make sense.

Tis strange,-but true; for truth is always strange;
Stranger than fiction: if it could be told,
How much would novels gain by the exchange!
How differently the world would men behold!

Truth is stranger than fiction, but it is because Fiction is obliged to stick to possibilities; Truth isn't.

Truth is always strange

Truth is weirder than any fiction I've seen.