1.2 points out that, to become an expert programmer, I need to know the
common patterns of usage in the domain, I should be able to
predict/visualize the consequences of the actions under consideration.

But 1.2 just (you can’t be TAUGHT to be an expert!) introduce some common
types of processes: linear recursion, linear iteration, tree recursion, and
then something similar to that in Introduction to Algorithms (which means
there will be a lot tricky skills).

In 1.2.1 it has an explanation to recursive and iterative; it’s a different
experience hearing a recursive procedure generates iterative process…

Recursive processes are characterized by defered operations. Iterative
processes has fixed number of state variables, a fixed rule to update and
and (optional) end test.

Recursive process requires the interpreter dod additional work, while
iterative process has everything needed in the program.