“What is the industry that I want to be working in? Startups often don't go the way you expect, but you can learn so much, so I was thinking what do I want to become an expert at — if it doesn't work out, what would I like to have learned four, five, seven years worth of information about.”

Pick the industry, not the idea — assume the startup might not work

Alex's framework for picking what to work on: assume the startup may not work, then ask what domain you want to be an expert in after years of full immersion. He chose plants because the underlying science, climate-change tailwinds, and consumer adoption made the bet pay off regardless of whether Greg specifically succeeded.