Thor finds through the course of this story, the ingredients of a successful superhero life are - family issues, old and new friends and monster demons to fight - combined with the courage and will to run towards life's problems. This charming underlying lesson makes it a winning addition to Marvel moviverse.
Perseverance in the face of seemingly insurmountable odds and character development which seems to organically flow along with a coherent, easy comic flair - this is wonderful storytelling, alien to the Thor series till now.
Thor: Ragnarok is amazingly funny - a masterful choice by Marvel of giving a brilliant comedian-actor-visionary the helm for Thor's third outing.
Taika Waititi, the director is a real-life creative genius - go watch his previous indie-stuff for proof. The screen writers undoubtedly did a great job as well.
On the non-inclusion of Natalie Portman's Jane Foster from the first two movies, I feel this movie presents firm, irrefutable evidence that you don't necessarily need a major romantic angle (to the extent of the exclusion other wonderful story elements) for a superhero movie to be massively entertaining. Go watch it now!