One summer, when I was in high school, I took an introductory computer science class at the local university, which taught PASCAL. It was a long time ago, and the computer was some CDC something or other running WYLBUR, I think. The programming assignments were fairly trivial -- doing division by subtraction and counting the loops, implementing a bubble sort, etc.

What I spent more time with was playing around with the system. The default password seemed to be the last few characters of the username plus "87" or something like that, so I got access to a number of unused accounts to play around with. I didn't accomplish much, but I found the scripting language, with interactive commands, such as "echo" to be much more compelling than the totally batch-oriented PASCAL system. Once, I turned off the startup scripts or something for the entire class, so that the commands used for doing the assignments weren't defined. At a subsequent lecture, the lecturer said something like, "Somebody has been messing with the system [blah blah blah], and I assure you, they will be caught." But I wasn't caught, and they gave me an A. I never transferred the credit after I went to college for real, though.