As a frequent Startup Weekend mentor (and co-founder of a successful boot-strapped tech company), I have had plenty of real life exposure to the doctrines of lean startup. But a recent experience has started me questioning whether we are doing ourselves a disservice through slavish adherence to lean methodology and an overly prescriptive approach to starting up.

Let me be clear. The Lean Startup framework provides a solid foundation for anyone who has not previously been in business and for whom resources are scarce. Starting a business is hard and developing a new business model is especially difficult. Coming from a science background, I’m very interested in how Lean Startup takes an experimental approach to testing hypotheses. This makes a lot of good sense. What makes less sense is when being Lean constrains our imaginations.

But I think there’s a way to resolve these tensions. There are two fundamental issues faced by a new startup and (to put it bluntly) not much else really matters outside of these two.

1. Are you addressing a real problem that people will pay you money to solve?
2. Can you position your solution in front of those people?

If you can answer these two essential questions, you have a shot at building a business. If not, fail fast and start over. At the forefront of your mind should be that customers are your chief source of capital, not investors. Engaging with customers early and identifying their problems is essential. Gaining venture funding is not a business model. Most businesses in the real world are NOT funded by venture capitalists.

By all means deploy Lean Thinking in your startup to discover customers, create value and extend your runway without becoming reliant on external funding. Indeed, a successful first product iteration that earns an income stream can provide a pathway to explore bigger ideas in the future. But please don’t let Lean Thinking kill your dreams. Many of the greatest tech companies started small and created their own markets. Be an entrepreneur scientist. Keep experimenting. Entrepreneurship is a creative endeavour, which is why many of us are drawn to it.

Paul Spence is a commentator and serial technology entrepreneur, a co-founder of iwantmyname (a New Zealand based global Internet venture) and a mentor with Startup Weekends. You can follow Paul on Twitter @GeniusNet or sign up for a free weekly digest of startup, tech and innovation related events curated by him through New Zealand Startup Digest.