Board Thread:Questions and Answers/@comment-25148221-20140707021425/@comment-8986886-20140709153153

Mohrpheus wrote: Regardless of how ridiculous it sounds, given what Aizen is capable of, there really isn't any reason to doubt what he said. Ichigo has always been a variable that Aizen found fascinating, but never really planned around. EBtR even foreshadows the fact that Aizen undoubtedly monitored Isshin and Masaki; the fact that he even knew that Ichigo was the son of a Shinigami meant that he had to have.

Personally I believe that the reason why you should doubt Aizen's monologue is that he is deception incarnated, and that he will lie to, and manipulate, anyone with a straight face; his actions over the past century should be a good indicator of this. There's really no reason to assume that Aizen either spoke the truth, or told Ichigo nothing but lies. Since a lie is more believable when it's partially true, I'm sure Aizen mixed truth with lies until his speach became convincing enough for Ichigo to at least consider that everything he said might be true. That's basically what a master-manipulator does on his free time.