The Last Jedi does not ruin anything set up by The Force Awakens. Everything in TLJ fits with exactly what Han says happened: “One boy, an apprentice, turned against him and destroyed it all. Luke felt responsible. He just…walked away from everything. There were a lot of rumors, stories. People who knew him best think he went looking for the first Jedi temple.”
Luke was not reverted back to a previous version of himself. Just because you have success in your youth is no guarantee of success later in life. On the contrary, experiencing great success earlier in youth can make INEVITABLE failures that much harder to cope with.
Losing a child can rip a family apart. It is compounded exponentially if one of the family members blames themselves for the loss. You can hear the anguish when Luke laments how Leia trusted him with her son.
Yoda does say Luke is looking away at the horizon again, but it’s different this time. When he was younger, he was obsessed with the future and adventure at the expense of the present. He needed to learn focus. Now in his old age he is dwelling on the past at the expense of the present, and missing the opportunity that Rey presents.
Luke is not even honest with himself about exactly what happened. He tries to unburden himself by blaming the Jedi way. Only when he accepts his own mistake and finally forgives himself is he able to learn from the experience. This is a hard lesson to learn. Sometimes it is harder to forgive ourselves than the forgive others because we hold ourselves to an unattainable perfect standard.
Luke then puts on an awesome display of Force mastery in one of the most beautiful and poignant moments of the entire saga.
The Last Jedi is an absolutely wonderful movie.
So Star Wars is now a learning-lessons-about-life-meta-documentary which uses a fictional space fantasy fairy tale as a backdrop some old bearded guy invented in the 70s?
Meh.
Star Wars should be about escapism, not realism.