Update README.md

Author: mybrainishuge

README.md

@@ -72,6 +72,8 @@ This function doesn't do anything meaningful, but hopefully it demonstrates the
 12. Resume the initial invocation from step 1 where it left off (in-between steps 3 and 4)
 12. Return out of the initial invocation
 
+Note that the value returned from the base case (step 9) gets returned to the previous invocation (step 4) on the stack. Step 4's invocation takes that value and returns it to the invocation that preceded it (step 1). Once the initial invocation is reached, it returns the value to whatever invoked it. Through these steps, you can watch the call stack build up and once the base case is reached, the return value is passed back down as each invocation pops off the stack.
+
 Due to the way the execution stack operates, it's as if each function invocation pauses in time when a recursive call is made. The function that pauses before a recursive call will resume once the recursive call completes. If you've seen the movie [Inception], this model may sound reminiscent to when the characters enter a person's dreams and time slowed. The difference is time doesn't actually slow with recursive invocations; rather, it's a matter of order of operations. If a new invocation enters the execution stack, that invocation must complete before the previous can continue and complete.