You can get the "car" (couldn't they have thought of a better name?)... Did I get car and cdr mixed up again?I can't imagine how I could be so careless.

In Common Lisp, you may freely use 'first' instead of 'car' and 'rest' instead of 'cdr' - they're completely identical. I tend to use first/rest when I'm thinking of something as a list, and car/cdr when I'm thinking of it as a cons cell, but that's hardly a hard and fast rule, even for me.