I am sitting in a taxi in Hangzhou and look out through the side window. I watch the houses along the street and sense that I have been at this spot before only to discover a few moments later that this was again a new place. Chinese cities are vast and you can go for hours in a taxi and everything looks the same (or almost the same). Our minds seek the familiar and try to map new impressions to previous experiences. That is the reason that I am getting these flashbacks of having been at this spot before. This is actual a useful feature of our minds to store and index pieces of information. (With indexed I mean that the information pieces are retrievable.) Thus we build up an indexed repository of information pieces. The more experience from a field, the larger the repository. Expertise in a field is said to consist of a general problem-solving capability combined with an indexed repository of about 100,000 pieces of information. Is it useful? Yes, it helps us to rationalise our lives and we can recognise patterns. Does it limit us? Yes, it sometimes does. When we learn new knowledge we have a natural tendency to map the knowledge onto our pre-existing mental models. But sometimes truly new knowledge is not mappable and we need to adjust our mental models. That is what we call “double-loop learning”.