• Straightforward refutation of the old idea. This complete refutation is atypical. More likely the new knowledge doesn’t contradict the old one, but it may modify it in some way.
• The new knowledge revises a simpler picture by filling it with more complex details. This is similar to adding new knowledge, although because the older, simpler view of the issue has been overwritten with more detail, there is some unlearning going on.

When something contradicts your current understanding, you are likely to dismiss it. This may be adaptive in a world where a big part of the information you encounter is false or is constructed to manipulate you. Things that you don’t currently believe are more likely to be false. 

However, this confirmation bias can make it harder to unlearn when that’s valuable to you.

Most of our false or doubtful assumptions about the areas that impact our lives are never examined. 

We use these assumptions to operate, but because they aren’t actively reflected upon, studied or challenged, they maintain their full force, even if fairly simple arguments could overturn them.

• Seek additive knowledge in familiar areas and then use that new knowledge to start pulling up and modifying old knowledge.
• Seek other people’s experiences of the world. Travel, in this way, can be a potent form of unlearning.
• Be more varied and bold in your experiments in life. Pure randomness can have a destructive quality to it. However, if you avoid obvious risks, many directions in life can be explored more thoroughly than most people do.