Why do we bother with dice ware? Is rolling dice and looking up in a printed book (or using a digital analogue) a string of N random words any more secure than simply repeating a word or two N times?
According to one online entropy calculator, at one hundred trillion guesses per second, it'd take 1.24 hundred trillion trillion centuries to crack my delicious password. And it's super easy to remember. And I don't need dice. Even my grandma could have a memorable and strong password: "type tophat seven times".
I do realize that a formula-based password violates Kerckhoff's Principle, and that using a word relevant to a target would strengthen a targeted attack, but in general terms, is there any theoretical security difference between random words of minimum total length T versus one word repeated sufficiently to reach length T?