In a "fresh out of school / fresh out of first job founder-wanting-to-build-a-startup" context, you often start with no connections, no capital, no world-class skills, no team, no game-changing idea. The only variable you can control is the amount of effort (time) you put into the venture trying to find something that works before you can no longer afford ramen. The hours are justified in that scenario, because you have no other resource to leverage outside of time.<p>Years later, when you're already comfortable, have a rich network of experts and trusted past associates, have easy access to capital, have decades of experience of building businesses, and a deep understanding of an industry of two? Yeah, you don't need the long hours, you're fine.