Demis Hassabis, the founder of DeepMind, experienced a significant career shift after an early failure with his video game, *Republic: The Revolution*. Despite the game’s collapse and poor reviews, Hassabis's initial conviction in his vision paved the way for his later successes. Author Sebastian Mallaby's book, *The Infinity Machine*, explores Hassabis's journey and the broader themes of conviction versus delusion in entrepreneurship. Mallaby argues that many successful entrepreneurs, like Hassabis, navigate a fine line where boldness can lead to either groundbreaking success or disastrous failure. The concept of the "fluency test" emerges from Hassabis's experiences. During the development of DeepMind’s protein-folding initiative, AlphaFold, he learned to distinguish between productive brainstorming and stagnation by observing the team's engagement. If the room buzzes with ideas, potential exists; if it falls silent, the project may be in trouble. This shift in approach reflects a maturity in Hassabis's leadership, moving from a mindset that prioritizes unwavering belief to one that values open dialogue and realistic assessments of capabilities. Mallaby highlights how Hassabis’s communication strategy contrasts sharply with the typical Silicon Valley approach. Many founders make ambitious announcements about future plans, often without solid backing. In contrast, Hassabis focused on showcasing actual achievements, such as his work published in *Nature*. This strategic emphasis on credibility helped build trust and excitement around DeepMind’s capabilities, demonstrating a savvy understanding of reputation as a vital asset in tech. Timing is another crucial element in entrepreneurship, with Mallaby noting that many startups fail not due to flawed ideas but because they enter the market too early. Hassabis exemplified this with his knack for sensing shifts in scientific trends, termed “scientific taste.” His ability to recognize when technologies were about to breakthrough, like reinforcement learning, positioned him ahead of the curve. This foresight, combined with his learned lessons from earlier setbacks, underscores the complex interplay of confidence, communication, and timing in successful innovation.