I was playing Star Wars Lego II the other day (for like the fourth time), and when the Luke character enters Yoda's hut, it got me thinking about the scene in Yoda's hut in ROTJ.

So I watched that scene and realized the moment when Luke becomes the first of the new Jedi (versus the last one trained under the old Jedi Order).

Early in their conversation, Luke calls Yoda "Master" as in "Master, you can not die" and "Master, is Darth Vader my father?"

When Yoda avoids answering him, Luke then says "Yoda, I must know" without using Master first. I think that is when Luke begins his independence from Yoda and begins his path as the newest of the Jedi Order and future Grand Master.

Luke began talking to Yoda as an equal (or almost equal) rather than this exalted being. I think that shift in attitude is what allowed Luke to surrender to Vader on Endor and what allowed Luke to stand tall against the Emperor and declare, "I am a Jedi, like my father before me."