To me Luke's entire arc is about, how do we reconcile mythology and reality? In TFA, Luke Skywalker has become a legend, a myth. But the reality of his own journey from his perspective is steeped in impulsiveness and failure. Luke has retreated from the story because the stark reality of his own flaws (which he had throughout the OT, and which have been reinforced for him many times by his mentors) has created the impossibility of living up to that legend. Rey turning up, offering him back his father's lightsaber – that's his worst nightmare, the myth catching up with him. So of course he's going to reject it.
But the reason why TLJ worked so well for me was, Luke realises that he can deliver on the legend – face down the entire First Order with a lightsaber, confront Kylo and achieve a victory of sorts (saving the lives of his sister and the remnants of the Resistance) – but he has to "reach out" with the Force, the thing he's come to distrust most because of the ways it's amplified his own weaknesses, to achieve it. This communion brings him the peace he needs – he can finally go out with both sides of his nature, who he really is and the myth he has become, reconciled. For me it doesn't conflict at all with the character we saw in the OT - he's still fundamentally ruled by his impulses, not all of them good. The kind of impulses that make you think about killing your own nephew in his sleep because you're afraid of what he might become if you fail – even if ultimately you're one of the good guys and you're not going to act on that impulse. It wasn't the arc that I imagined, but I love it a whole lot. Just my 2c worth.
Spoiler:
Definitely! 
