I think Muad'dib's Mentat training was one reason he didn't turn out to be the Kwisatz Haderach that the Bene Gesserit were counting on. Besides the whole part

I think Muad'dib's Mentat training was one reason he didn't turn out to be the Kwisatz Haderach that the Bene Gesserit were counting on. Besides the whole part where Jessica jumped the gun and jiggled her ovaries to produce Duke Atreides a son, instead of the daughter who was supposed to grow up to marry Feyd-Rautha.