"It's a pity nature isn't divided into the same categories as universities."

We need categories to be able to handle the huge amount of information we use and control. That's why we have a hierarchy of folders and files in our computer, and that's why universities are categorized into faculties and departments. Categorization helps you, but can also prevent you from using what you know about one field in another.

There is a well known → problem in education called the transference problem. If you teach something in one context, students most likely will not be able to use that knowledge in another and build → synergies.  >>>

A rigid budget system is also organized hierarchically according to categories. Even individuals → unconsciously create a budget system.

In one of their experiments K&T found that if a person purchases theater tickets at say, $100 and accidentally loses them, he will NOT buy new tickets. But if that person lost $100 he would still go and buy the theater tickets on the same day. The explanation is that after purchasing the tickets, the money already "belongs" to the theater budget. When lost, new tickets are not purchased because the "theater budget" has been spent. When losing $100, the money had not yet been "assigned" to a certain budget category, so the theater budget is still available. 

When → solving problems we also use a categorization system to help us deal with the vast amount of data involved. For example, we make an almost automatic distinction between what's relevant to the problem and what's not. The problem is that some information may not seem relevant to the PROBLEM, but may be highly relevant to the SOLUTION.