What are the biggest mistakes that first-time founders make?

@sentry_co André, you make a compelling point about the nature of mistakes and how they form the foundation of our learning and mental models. I completely agree that pain from mistakes can be a great teacher. As you said, mistakes teach lessons far deeper than advice alone ever can. The idea of letting your kid touch the candle to learn about heat makes sense because it builds that direct, rooted understanding, much like how entrepreneurs forge their own paths. However, I think there's an important nuance here. While failure isn’t the enemy but rather the fuel for growth, we should be cautious about the types of mistakes we make. It’s true that avoiding all mistakes might limit our learning, but there’s also a balance. The goal is to make the right kind of mistakes, those that push you forward rather than break you down completely. Not every mistake should be embraced if it jeopardizes your mental or physical health or puts your entire progress at risk. Using your example of the candle: sure, touching the candle helps your child understand the connection between heat and pain. But you wouldn't make him jump into a fire just to learn how dangerous it is! Some mistakes are too costly and can cause damage that is hard to recover from, and this is the same for entrepreneurs. Not all mistakes should be embraced—especially the ones that can derail your health, well-being, or long-term prospects. For instance, when I first moved to Germany as a refugee, I faced relentless challenges, and through all that trial and error, I developed resilience. I constantly pushed forward, learned German quickly, and built relationships that helped me grow. But at some point, I found myself making mistakes that affected my well-being—mistakes that weren’t necessary to the learning process, but more like miscalculations that worsened my health and state of mind. These weren’t the constructive mistakes you talk about but mistakes that could have been avoided had I been more aware or mindful. I think there’s a danger in entering the "feedback loop from hell", where one bad decision or a wrong mental model drags you down into a space where you keep compounding your suffering. This is where I’d argue that some mistakes are too costly to ignore. It’s one thing to move slow or reinvent the wheel, but if your mistake results in the breakdown of your physical and mental health, it becomes harder to recover and stay on course. I've had moments where my health collapsed after pushing too hard, and suddenly, the price of those mistakes was no longer just a delay in progress but a long-lasting struggle with my own capacity to perform. The mental and physical toll affected my ability to work on my business or even function properly. And that's where I think we need to be cautious. Some mistakes can derail us so much that the process of bouncing back becomes exponentially more difficult, making it crucial to avoid certain kinds of failures. That’s why, when we set high goals, it’s important to differentiate them down into achievable steps, each challenging enough to push us but still within the realm of possibility. By doing so, we give ourselves the chance to learn from mistakes while maintaining a reasonable probability of success. In other words, it’s about making sure that the mistakes we make are ones we can learn from and recover from, not ones that leave us in a downward spiral or prevent us from continuing the journey. I agree with your point about being wary of external advice. Startup advice often sounds flashy but lacks depth, especially when it’s out of context. Sam Altman’s case with OpenAI is a great example. People see the success and hear the mantra of "fail fast," but they don’t see the decade of consistent, behind-the-scenes work before finding PMF. But there’s also another side to this—while no one can fully understand your situation the way you do, some advice can help you avoid avoidable mistakes. It’s not about blindly following it but rather integrating it selectively, like a feedback loop that allows you to test what works for you without diving into a death spiral. In my own journey, there were times I wished I had learned certain lessons sooner—about balance, health, and making smarter, more calculated mistakes. Yes, you have to make errors to grow, but you shouldn’t be so consumed by them that it prevents you from moving forward. The key is to find that balance where you're learning from failure without letting those failures consume you. You don’t have to burn yourself out to be successful. Ultimately, I think it’s about making the right kind of mistakes—those that you can learn from and recover from without destroying your ability to keep moving. You can’t avoid failure entirely, but you can try to avoid ruinous mistakes. We all have a limited capacity, both physically and mentally, and I believe it’s crucial to protect that so you can make those incremental improvements over time. Fail forward, but fail wisely.