Sam Altman, CEO of OpenAI and former president of Y Combinator, once said: “Intelligence is easy to tell in 10 minutes. Determination is much harder.” This statement captures a practical principle in hiring, investing, and evaluating talent. While sharp thinking and quick insights can be observed almost immediately, a person’s ability to persevere through challenges only becomes clear over months or years.

Born on April 22, 1985, in Chicago and raised in the St. Louis area, Altman studied computer science at Stanford before leaving to co-found the geosocial app Loopt. He later joined Y Combinator, eventually leading it, and since 2019 has served as CEO of OpenAI. Known for product judgment, public speaking, and identifying ambitious projects, Altman’s philosophy prioritizes long-term execution and disciplined work.

In the context of startups, Altman explains that intelligence is visible in conversation, problem-solving, and fast comprehension of ideas. Determination, however, is a pattern of behavior: showing up after setbacks, learning from failures, and consistently tackling difficult tasks. YC interviews often misjudge this trait, as it requires observing persistence over time rather than a brief meeting.

Altman’s broader philosophy emphasizes designing systems to test endurance, such as trial projects, long sprints, and careful follow-ups. His public statements advocate for hiring “missionaries, not mercenaries,” moving fast, and focusing on the most important tasks. Key quotes include:

• “The question I ask myself almost every day is, 'Am I doing the most important thing I could be doing?'”

• “Move fast. Speed is one of your main advantages over large competitors.”

• “AI will change everything—and that's both exciting and terrifying.”

In essence, Altman’s observation serves as a reminder for leaders and teams: intelligence can open doors, but determination and grit ensure you stay in the room and complete the work. For long-term projects, sustained effort is the real predictor of success, surpassing the value of an immediate bright impression.