The idea is interesting, somebody who is struggling in life gets the chance to relive a certain period of it. There are a lot of interesting scenarios within this story line, sadly none of them are explored at all. The main story holds no relevance to the series and could be extracted from it without anything feeling off.
The idea of the show is to resocialize somebody who has shut himself of from society by letting him relive his youth. Oddly the main character doesn't really need to be socialized. His personality is warm and accepting from episode one. All the man needs is a job and some trauma-therapy. There is no real character development going on here as there is little progress for the main character to be made.
That aside the story still might be interesting if you'd properly explore how an 27 year old man might feel skipping backwards in time, how a grownup interacts with the values and problems of teenagers, sadly this potential is left untouched. The main character does not come across as an adult who went through very depressing periods in his life. Instead he feels like a teenager himself, getting embarrassed over banal things, overly focused on group-interactions, accepting the authority of teachers over him (having him drop smoking, as they think of him as a teenager).... There is no conflict caused by his mental age in this new situation and there are very few moments where he seems somewhat mature. These moments are the better parts of the series, very sad to see that this was not integrated in the story.
All in all this series has some loveable characters going through minor problems of growing up, everything else is an unused extra which leaves much to be desired. Sad to see an interesting idea falling flat on it's face. Watchable but nothing more.
