Your best ideas are probably your biggest blindspots

I used to think conviction was good. The more certain you were, the faster you could move. Turns out conviction is just belief with better PR.

Watched a founder kill his company last year. Not because he was wrong about the market or the product. He was wrong about why he believed what he believed. Never questioned it. Just kept building based on assumptions that felt like facts.

The dangerous beliefs aren't the ones you argue about. They're the ones that just sit there, running in the background. You don't defend them because you don't see them. They're just... how things work.

Your brain is optimized for efficiency, not truth. Once it decides something, it starts looking for evidence that confirms it and ignoring everything else. This isn't a bug. It's how you stay sane when processing thousands of inputs every day.

But for founders, this efficiency becomes expensive.

You hire for "culture fit" without defining what that means. You avoid enterprise sales because "that's not our customer." You stick with your tech stack because "we know it well." Each decision feels rational in the moment. None of them get questioned.

I started asking founders a different question in our meetings: "Why do you believe what you believe?"

Not "What do you believe?" That's easy. Everyone can tell you their strategy, their thesis, their plan. The why is harder. Most people can't answer it without reverting to the original belief.

"We're focused on SMBs." Why? "Because enterprises move too slow." Why do you believe that? "Because... everyone knows enterprises move slow."

See what happened? The answer looped back to the belief. No actual evidence. No specific experience. Just a thing that everyone says, so it must be true.

When you ask "Why do I believe this?" you're forcing your brain to trace backwards. Not to justify the belief, but to find its origin.

Sometimes you find data. "We tried enterprise sales for six months, closed zero deals, our ACV was too low to make the sales cycle work."

Sometimes you find experience. "I worked at three startups that died chasing enterprise deals when they should have focused on PLG."

Sometimes you find... nothing. Just an assumption you picked up somewhere and never examined.

That third category is where your blindspots live.

One founder I know spent eight months building features for a persona that didn't exist. Not because he hadn't talked to customers. He had. But he believed "developers hate sales calls" so strongly that he dismissed every signal that contradicted it. Turned out his specific type of developer actively wanted implementation help. He just never asked why he believed they wouldn't.

The beliefs that trap you share three characteristics:

They feel obvious. If someone challenges them, your first reaction is "well, obviously." That obviousness is a warning sign. Obvious to who? Based on what?

They're often borrowed. You heard a successful founder say it at a conference. Read it in a blog post. Picked it up from your last company. Doesn't mean it's wrong. But does mean you never pressure-tested it in your context.

They're expensive to question. Changing this belief would mean rewriting your roadmap. Rethinking your positioning. Admitting you've been optimizing for the wrong thing. So you don't question it.

The question isn't just "Why do I believe this?" It's what you do after you can't answer it well.

One approach: Ask what would have to be true for you to be wrong. Not what is true, what would have to be true. If you can't imagine being wrong, you're not thinking clearly.

Another: Look for the evidence you're ignoring. Your brain is filtering it out automatically. What are customers saying that you keep dismissing? What patterns keep showing up that don't fit your model?

A third: Test the cheapest version of the opposite. You believe enterprise sales won't work? Take one enterprise meeting. See what happens. You're probably right. But if you're wrong, the cost of finding out now is way cheaper than finding out after two years of doubling down.

I'm not saying abandon your convictions. Conviction helps you move fast when you're right. But conviction without curiosity is just stubbornness with a nicer name.