Willis Carriers vision was not the first lucid dream recorded in history, but it very well may be the most significant, and is a fine introduction to the topic. The invention of the air conditioner ushered in the modern age, making life bearable for the first time in human history.
How does a man discover something so consequential and practical in the non-dream world while in the dream world? How does he gain the ability to understand that he is dreaming and act proactively within the dream?