Don't do Psychology, but I think you've got it in the bag. In a way, I think mnemonic devices can be equated to hynopaedia. It helps for people to recall the information, but the individual may not necessarily understand the information that is to be remembered. If someone was to repeat a sentence a thousand times a day to you, in your subconscious, you may recall what the person said, but you won't necessarily understand the meaning of it. An example can be found in reference to the unit circle. Many people remember the term CAST, and hence is able to recall in which quadrants sine, cosine and tangent are positive. However, they may not necessarily know why it is that way (not being able to understand the stuff behind the mnemonic acronym).
Lol, I hope I make sense. :p