I think it was the Youtube channel "Generation Tech" that went into how, in some Legends books, the Sarlacc somehow extracted memories of its victims and since Boba was partially digested, he gained many of them. Either way, yeah - there's more to the experience than we've been shown thus far. The sail barge wreckage had ceased smoldering, IIRC, so it was probably a few days, or at least many hours, that he was down there. Since he was gasping for air, he could have also suffered some brain damage or something from oxygen depravation, etc...