After many, many and many more story arc episodes, it's nice to get back to the Monster of the Week even it was a little lame. The episode did touch on the subject of Sam going back to a normal life after ridding the world of demons.
It's an odd relationship with the brothers this year. They are both looking for normalcy, but it two completely different ways. Sam wants the white picket fence, dog and adoring wife that he had while Dean was in Purgatory. Dean's been in survival mode for a year and wants to get back to the only thing he really knows how to do: hunt.
In this episode, the brothers defeat an Mayan warrior that has stayed young for centuries by making a deal with one of their gods. The only caveat was that people had to die to keep him young. He eventually tired of living and killed himself, but when his organs were harvested and given to sick people, they discovered they could become almost superhuman by doing the same ritual.
When it was all said and done, Dean enjoyed the normalcy of defeating the bad guy and saving people. For Sam, it just reinforced his departure from normalcy. I don't know where the writers are going with this, but Sam can't expect to quit cold turkey. Even if he gave it up, Sam's got enough enemies out there that eventually someone is going to find him.
He's nearly ended and saved the world. He's killed hundreds of creatures and left a wake of bodies behind him. For the Winchester brothers, what we think of as normal isn't an options.