A Graduate Course in Applied Cryptography
I never really understood the appeal of nerding out on cryptography. As soon as you get it in your mind to do some fun innovating people tell you (correctly) to "never roll your own crypto". Unless you're super talented at math (on the PhD level) and actually could roll it on your own then I don't really see why you shouldn't just abstract it in your head as a solved problem like modern day assembly code arcana (though I guess I'm curious about other peoples perspective).