Democritus, fr. 103 (Stob. IV 34, 58)

“Good things rarely happen when you look for them, but bad things happen even when you don’t.”

διζημένοισι τἀγαθὰ μόλις παραγίνεται, τὰ δὲ κακὰ καὶ μὴ διζημένοισιν