Recursion HALP

Hey /prog/, I must say my understanding of recursion is shit (never really dealt with recursion in all my days of writing bad code). How should I go about thinking about it?

inb4 flaming: I understand the recursive concept in some contexts, such as when it is used in a factorial function, but when it starts getting more ambiguous (say, exercise 5, ch. 2 from ANSI Common Lisp) it's ugly.

inb4 RECURSE MY ANUS

>>20
Umm.... a function can be a variable. This happens more often than what you think you fucking moron.

Again, you are stupid. Also, showing the entire evaluation will not show you the order of evaluation. Again, at what point and time you do evaluate 'fact' to a value? At what point and time do you multiply all the numbers? Again, you don't bother to explain it. So again, until you can answer my questions, you should maybe stop giving shit advice, learn a few more programming languages, and attempt to write a compiler before you open your dumbass mouth again.