This episode goes into the hypothetical idea of what if Shawn had never moved back to Santa Barbara, when he realizes that he really messed up on the case. It helps him become a lot more humble going forward, and shows a sign of character growth. This growth is further shown when Shawn starts to show some ownership of his character flaws to Lassie, and how much better Shawn would be as a person if he behaved in a more well natured matter. It really sets the stone for the rest of the series, where Shawn starts to realize that with being together with Juliet, he has no choice but to become a better person, and not be goofball that he used to be for the first 35 years of his life.
Review of The Polarizing Express
