Bias, error, and ego are instances of rational or instinctual over-compensations; one moves toward a value or goal but does not adequately “slow down” to meet it when it arrives, i.e. there is an inertia from past pre-value or pre-goal states causing one to continue to move forward and past it.
We are not robots or AI, we all have a lot of psychological “baggage” and incentives, and most of consciousness is still “unconscious”. Because of this, our instincts and our reason attempt to adjust to new information/reality but cannot quite orient themselves adequately to this new perspective due to needing to also adjust all that extra “baggage” too, which is not so easily and so accurately re-assigned (because it is larger, it weighs more, it is harder to see, etc).
When the over-lap, the over-compensation occurs there is both an instinctual/emotional and a rational effect; the former effect is that we feel something like ego or vanity, we are drawn to at least partially not dis-align ourselves with that large unconscious inertia, we attempt to value it, to value the over-lap with respect to both the goal and the pre-goal states, and a combination of clarity and confusion, humility and ego, vanity and objectivity occurs; the latter effect is that our ideas manifest a kind of spreading confusion and flux-ness, new ideas are engendered which exist only to re-align or just to realize both the pre-goal with the (now having caught up with) goal as well as the goal with the post-goal. These ideas create a ton of confusion because in our naiveté of largely un-intended consciousness we rank these ideas as equal categorically and ontologically speaking with the rest of our ideas, such as those related to the goal or value itself; when you combine this idea confusion with the context of psychological-emotional confusion as per the former effect, you get a very pernicious situation in which more incentives are temporarily created to dis-align from truth than to align with it.
If a separate, strong instinct and rational motive to truth itself is not present in the mind, this temporary incentive-warping becomes more permanent, as its remainders/effects cannot be fully accounted for and multiply outward across the mind at large. Basically the person loses his/her footing and becomes unable to distinguish pre-goals from goals from post-goals… becomes unable to know (respond to, posit, and evaluate) his/her own values, own self.