When Buffett mentions the chewing gum and aviation industries, the comparison illustrates how important choice is. The aviation industry has not brought any profits to investors since its inception, while chewing gum has consistently brought substantial returns to investors. Why? There are many reasons, including economic characteristics, competitive landscape, consumer loyalty, etc. Something particularly interesting is that aviation is high-risk with low returns, while chewing gum is low-risk with high returns. The same goes for coin selection in the cryptocurrency industry. Do you prioritize big over big or small? What are the odds and risks? In fact, when it comes to the fundamental issue of investment, whether it's value investing or fighting for dirt dogs, the previous analytical framework and ability requirements are different, but the ultimate betting decision principle is the same.