You can’t truly understand everything about a business in 1 week. It took me 10 years and I am still learning new things about BYD. It is a continuous learning process. You could spend a lifetime studying a business or industry, but in a few seconds I can tell you whether or not I like it. You want to build [knowledge and continually learn]. There is not set preparation.
His comment "but in a few seconds I can tell you whether or not I like it" reminded me of these posts:
Warren Buffett quote on filters
Alice Schroeder on Buffett’s filtering process