Why did Luke say "It didn't scare me enough then, it does now"?

Question

In Star Wars: The Last Jedi, after Luke has witnessed how powerful Rey's ability to use the force is, he says to her:

I've seen this raw strength only once before. It didn't scare me enough then. It does now.

When Luke talks about seeing that raw strength only once before, presumably he is referring to Kylo Ren. But if that's the case, then saying "it didn't scare me enough then" doesn't make sense. Luke saw Kylo Ren's strength and it scared him enough to consider killing him in his sleep. So what did Luke mean exactly?

Answer 1

He means it took him too long to become afraid of that strength in Ben Solo. It took long enough that he didn't try to divert him from the Dark Side until it was too late.

Yes, he considered killing him while he slept

But chose not to, seconds too late to keep Ben from realizing he'd considered it

but he didn't reach that point until it was too late. It didn't scare him enough when he first saw it, and he let Ben become Kylo.

'Now', with Rey, he recognizes it sooner and it re-affirms his determination to not teach her.

Answer 2

Luke still has lingering doubts about his failure with Ben Solo. We see that Ben/Kylo and Rey are both natural Force users, with some sort of innate skill (i.e. Anakin Skywalker) in using the Force. While we still don't know much about young Ben Solo, we know that Luke was entrusted with him to teach him the ways of the Force, and there was an implication that Ben was already somewhat troubled, something that Luke thought he could overcome, but failed to do, possibly because of Snoke's hold on Ben.

Remember, also, that this happens right after

Rey taps into the Force and gets drawn towards the "dark side hole". Luke is horrified she would go there, and immediately fears a reprise of Ben's fate.

The implication is he'd rather see the Jedi die out, than train another potential Dark Sider/Sith.

Answer 3

The theme of a Jedi Master taking on an apprentice who's very strong in the Force who then turns to the Dark side is a major motif of Star Wars.

Yoda faced the same concerns with both Skywalkers, in Episode I and Episode V, with Anakin succumbing (and in the process wiping out Jedi Order) and Luke coming perilously close.

Later in the movie, Luke talks to

Yoda's Force ghost

and discusses that he's basically made the same mistake with Ben as Obi-Wan with Anakin (taking on an apprentice who was too strong in the Force, and losing the apprentice to the Dark Side).

This is a direct parallel to Rey for Luke - she's basically another Ben/Kylo (and Anakin/Vader) risk. Except, now that he already had a failure with Ben, he's far more aware of the risk and correspondingly more scared of it.

Answer 4

With new information, I think Luke was not referring to Ben Solo. That's only what the audience was expected to believe. In fact, he was talking about the raw strength of Palpatine, who he faced only "once before" and now believed to be dead. Irrespective of whether he figured out her bloodline connection, I believe he sensed Palpatine's power in Rey. Palpatine's power didn't "scare him enough" in that he underestimated the power and was completely outmatched, saved only by appealing to the good in his father.

Also, I doubt Luke was referring to Ben/Kylo because he is never really portrayed as someone with such raw power that Luke should feel deeply afraid of him. Luke was more just mad at himself for "failing" Ben. Luke could have killed him easily, had he really tried. But that's not the way of the Jedi which is why he hesitated. His exile was not because he was afraid of Kylo.

Answer 5

The full line from the movie is:

Luke Skywalker: I've seen this raw strength only once before, in Ben Solo. It didn't scare me enough then. It does now.

He's talking about how he knew that Ben had considerable power with the force, but Luke didn't take enough precaution against the dark side and Snoke tempting Ben away from the light, until it was to late.

Answer 6

From the rise of Skywalker we now know that

Luke was probably referring to sensing Palpatine’s strength in Rey. Not comparing her to Kylo

Answer 7

It was a reference to his underestimation of Palpatine and Rey's power by proxy.

Yoda said "Do not underestimate the power of the Emperor". Luke did, and his father saved him at the cost of his life. This was in the works from Episode VII on. It's all been in the works from day 1. The Darkside as embodied in the Sith, is now no more just as promised with Episode XI; the fallen Jedi are celebrating.

Answer 8

  Unfortunately, many lines in "Last Jedi" don't have much sense in-universe. They were thrown around just because they sound cool enough for teaser, to build fan's expectations. This particular line hinted that Rey is powerful in the Force on the level of Palpatine or Snoke (if Luke ever met him). Also this hinted that she could be descendant of one of them, explaining her abrupt mastery of lightsaber (only two or three days needed) or abilities like Mind Trick. We now know that it is not so, therefore this line does not have much sense. Note that Kylo Ren certainly is not that powerful, nor did Luke witness his strength only once because he trained him for some time, and even contemplated killing him which he would not do if Kylo displayed Dark side tendencies just once.