Discipline
Everyone thinks they're disciplined. Ask around - you'll be hard-pressed to find someone who admits to being undisciplined. It's like asking people if they're good drivers. The belief itself is so universal it should make us suspicious. Having strong opinions about how things should be done isn't discipline. Neither is knowing what the right thing to do is. I've met founders who are very intelligent and great people, and yet poor at execution. The gap between knowing and doing is where discipline lives, and most people don't even realize there's a gap. They think understanding the path is the same as walking the path.
Here's what discipline actually is: doing things you don't want to do, repeatedly, when no one is watching. Many founders, myself included, have an innate inclination towards certain tasks - e.g. designing in Figma, coding, reading substack etc. Those tasks can be helpful for building startups, but they are not really about discipline. Real discipline is answering customer emails when you'd rather be building features. It's reviewing boring but critical metrics every morning. It's having difficult conversations with team members instead of hoping things improve. The Japanese have this figured out - their culture doesn't celebrate discipline; it assumes it. In Chinese, the word 忍 (to endure), literally means a knife on your heart - a perfect picture of how it feels when you force yourself to stay disciplined.
Self-discipline compounds, but it also decays. This is what makes it particularly crucial for startup founders. The whole mythology around startups celebrates doing hard things - "do things that don't scale," we tell ourselves. But doing one hard thing isn't the point. It's doing it again tomorrow, and the next day, when the novelty has worn off and things aren't always working and the path feels uncertain. Perhaps discipline is the highest expression of self-belief. By overcoming your own impulses, you rise into the person you believe you can be.