I'm still in disbelief that Luke straight up dipped because of the Knights of Ren. Luke, the guy who stood up to the emperor. I feel like he lost someone incredibly important if he was so affected as to leave everything behind.
Luke was standing at a gravestone when Rey found him. My monies on this being his wife and Rey's mother.
That kind of tragedy- losing your school, your younglings, padawans, basically the future of the force in the Galaxy, plus your wife, and having 7 angry Emo kids clad in black, on an intergalactic hunt to murder you and your child sent by some ancient evil being.. Yea id erase those memories and hide my kid on a planet no one would look for her, drop off my old worshipper buddy Lars with a key to find me to look after her, and split too.
He's got 7 Knights, potentionally all force sensitive, hunting him, led by the son of his best friend he failed to protect from the dark side who killed his wife, what would you have him do? He's out searching for answers in how to turn them back maybe... Either way, he learned from Yoda so he pulled a Yoda and is in exile waiting to train the next "chosen" who finds him.
Ka is a wheel, after all.
That said, that feels like the "intent" to me- Rian Johnson having reins to take this in a direction he wants, be interesting to see if he goes the clean route or mixes it up a bit in 8. It's all implied but tenuous enough he can get creative with who is who, but to me Star Wars works best when it takes the simplist solution an embudes it with real emotion vs some convoluted plot twists.