Apparently he was just about to go and burn the Jedi books. Beats me why he needs the Jedi tux to do that, especially if he denied the Jedi.
EXACTLY! Why at that very moment? Why not a day before Rey showed up? Why not a month, a year or a decade? Why NOW? And why does Luke fold his robes and neatly place them on the shelf? My brain hurts from trying to understand TLJ. I hope the powers that be right this wrong.
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And base himself at the most sacred and obvious of Jedi locations.
According to Han, he left in search of the ancient Jedi Temple. But why search for something you want no part of unless he came to that conclusion after all those years in seclusion?