Wanting to optimize my path through school, I asked some senior people if that programming languages course based on Scheme was useful. I was informed that it's a toy language based on Lisp for teaching. I correctly assumed that this is something other than the real Lisp, a legendary language which can't be a toy. It being a university for grown up children and all, I didn't want to have anything to do with toys. The course was a prerequisite for a senior level compiler course, but I talked the prof into letting me skip the prerequisite and go straight to that compiler course.

Man, I sure dodged a bullet there. Some decade later, I got into Lisp in a big way (the real one); the rest is history.