Java Security

Hi,
I'm a grad student, CS major, and I wanted to post this in the 'training/learning' folder but it doesn't seem relevant to those topics - I hope this is the right folder for this question.

I am taking a Computer Security class and we're expected to memorize the DES algorithm. If I am given an input block and a set of tables, I ought to be able recall the algorithm from memory, generate the keys, and manually encrypt the block. If I did this every day for years, I've no doubt that I could memorize it, but I have been trying since the beginning of the semester I am not finding this easy to commit to memory, in comparison to the other algorithms we've studied. Every time I look at the algorithm, I think that recallling and executing it by hand is merely a rote drill that would be more reliably done by software. Yet there are many other algorithms in the textbook that I have memorized (albeit most are shorter, like AES) and would also be more reliably performed by software, but because I personally find them more interesting, I have memorized them with enthusiasm. Testing for primes, for example - software can do that more reliably and certainly more quickly than I can, but because it's a classic programming exercise and I find it interesting and intellectually valuable, it's easier to memorize.

Overall my class is great, I enjoy everything about it but can't seem to muster up any interest in the DES algorithm, even though it's so widely used and obviously an important development in computer security. I have already accepted that I'll have to take a loss on this particular topic for my final exam, but just out of curiousity, there must be security professionals on this forum - did you memorize DES by repetitive drilling, or did you naturally find it interesting enough to committ to memory?