The Little Schemer was what finally got me to internalize how to solve problems recursively. I'd taken a couple of college classes and could do it some already, but it took a lot more thought than solving those same problems in other ways.

About a third of the way through The Little Schemer, things just clicked, and what had been hard became pretty instantly easy.

Some of that was it building on existing knowledge, but I found the structure very helpful. The narrative is really just the glue around a well-designed series of incremental problems.