
Although some may critize that Luke wasn't the most put together of Jedi, from the time I first viewed "Return of the Jedi", at the age of nine, I could tell that he had certainly changed, i.e., grown up, since I last saw him in "Empire".
I suppose three things were responsible for this maturity: (1) Growing stronger in the Force, (2) Dealing with the concept that Vader was his father, and (3) Planning the rescue of Han Solo. I would say that it was in that order, because although Han was a good friend, perhaps Luke's best friend, it is usually the inner workings that mature us faster than the exterior ones.
When he walked into Jabba's palace you could tell there was a new manner in his ways. Yet, I wonder how much he let his mind wander back to his former days on Tatooine. While he constructed his lightsaber as a tool to bring Solo's freedom, was he wondering what happened to Fixer, Kim, and his other friends. Had they needed his saving when he was away? And what about Uncle Owen and Aunt Beru? Did Luke's mind ever ask what might have been if Obi-Wan had been allowed to train him at ten, when he could have felt the Imperials at his hut and rescued his relatives?
In the "Star Wars" 3-D comic series by Blackthorn (a four issue set beginning in 1987 and ending the following the year) the premier story tells of Luke, Chewbacca, and Han returning to Tatooine so Skywalker could sell his Aunt and Uncle's farm. He gave it to a former bounty hunter who was attempt to start a new, more peaceful, life. Did this happen, or when Luke passed the hut by speeder was it still burned out and filled with ghostly memories?
Chances are that, when dealing with Jabba, even when he first met him as a pre-recorded hologram, Luke's mind was cleared of these considerations. He had to focus on his mission.
Nevertheless, I believe it was these thoughts that Luke had to come to terms with before he could willing turn himself over to Darth Vader and allow himself to be killed by Palpatine (as he surely would have been had Anakin not intervined).