One evening last year, I was watching an insightful tech video on my computer. It was in English with Chinese subtitles. As I watched, a thought struck me: I wish I could just listen to the Chinese version. No need to stare at subtitles all the time. I could listen during my commute, before bed, wherever. Eventually, I actually built it. But from the moment the idea struck me to creating a product everyone could use, it took far longer than I expected. After the idea came, I tried a...