Bubbles happen when everyone realizes there is a gold mine somewhere, but no one knows how to find it. Some things are overvalued, some things are undervalued. Usually the gold is in a place where you least expect it.

The Netherlands had two flower bubbles, but not because people where crazy. People started to realize that this tiny patch of soggy land would one day be the biggest exporter of flowers and vegetables in the world. Flowers are clearly worth way more per kg than grain, but how much exactly? No one knows, but surely those tulips must be worth a lot.