These things occur so naturally in Scheme that I couldn't help but understand. After mastering the concept, I could then go back into my Pascal class and master the code. The point here is that concepts like these are universal in computer science. After you understand them, then you can learn the rules of any language in order to encode them. But it doesn't matter how well you have mastered the syntax of a language if you don't understand the meaning of what you are typing or the reason why it works.
Recursion serves as a prime example.
But after seeing the first recursive program in the Scheme text, I understood what it was all about. When we took the test on recursion in A.P., my whole class seemed to choke, with grades in the 60's and 70's, and the second highest score in the 80's. Thanks to my background in Scheme, I aced the test. I couldn't quite believe it myself. Scheme code is clear and easy to understand.