User blog comment:OnePieceNation/Brook's Full Goal/@comment-4132693-20120220114139

First of, Luffy's main goal to be pirate king is to travel the seas with absolute freedom. If i recall correctly, I want to point out that i think Luffy also made a promise to come back and visit Laboon (can't remember what the exact promise was). That being said, with Brook joining the crew, he has resolved to help Luffy and be a dependable crew member. In that case, here's my two cents: I think after conquering the grandline and NW, the SH crew will be labeled as the pirate king crew, this way they can sail without boundaries and will as a crew, visit laboon and take him with them. This will fulfill the promise made among Luffy, Brook and Laboon.

P.S. your blog is long for my sleepy eyes so i think i covered in my comment what i understand from your post