I Disagree. This "you only need one eye and one ear - two is redundant" approach to memorization is a root with the dire situation of today, in which I know youngsters with some diploma who can go "I thought that 5x8 was [any number]. Really it is 40?!".

While studying, in general, mnemonic hooks pose a foundation for further notions to become solid. Then, the whole of them become available micro-tools for reasoning.