It requires a lot of effort to overcome bias, perhaps years. But there are times when it is worth it.

There are also times when it's not worth it, in my opinion.

What perfection?

Rand contrasts "a conscious, rational, disciplined process of thought and scrupulously logical deliberation" with "a junk heap of unwarranted conclusions, false generalizations, undefined contradictions, undigested slogans, unidentified wishes, doubts and fears, thrown together by chance, but integrated by your subconscious into a kind of mongrel philosophy and fused into a single, solid weight: self-doubt, like a ball and chain".

I think it's possible to avoid becoming such a disgrace without scrupulously logical deliberation. Most people are severely biased but are not as unhappy or helpless as Rand's argument would imply. Trimming the excesses of our biases seems more reasonable than eliminating them, to me.