"I spent the first 18 years living on a remote moisture farm on Tatooine, and once I was able to leave, your much older self only had a couple days to tell me what the Force was and hint that I might be able to use it. 'Old Ben' gave me my father's lightsaber, and that was that." Luke isn't sure if there were Jedi who specialized in knowing the flow of time, but he's heard some rumours.

Then again, he's heard rumours that they stole children, and that seems like it must have been Imperial propaganda.