 Usually, when a mind flayer inherits a trait like this, it keeps it a closely guarded secret, because, were its peers to learn of it, the Illithid in question would most likely be killed.This is due to an Illithid legend of a being called the "Adversary".The legend holds that, eventually, an Illithid larva that undergoes ceremorphosis will take on the host's personality and memory in its entirety.