Explain why '' the cask of amontillado 'montresor is not crazy?

There is no reason to claim Montresor is insane except the element in his disclosure. He says that fortunato injured him a thousand times but doesn't give any example on how and why.Some readers conclude that he hasn't been injured and that he is delusional If Montresor has not been injured, then he is insane. But Poe could not have left the question of his sanity or insanity to hinge on a few words in the opening sentence of his story: "The thousand injuries of Fortunato I had borne as best I could, etc." If Poe wanted the reader to believe Montresor is insane, his creator would have given further evidence throughout the story. 

That’s nice! sounds really fun.