Yesterday it suddenly struck me what I think is so special about the most successful startup founders.

Let me first say that I haven’t met any of them in person yet. The part of London startup scene that I’m exposed to is not your classic Silicon Valley breed of Stanford and CalTech grads, ex-Googlers and friends of Marc Andreessen. People here build taxi ordering systems and video curation apps. They may be fine pieces of engineering, but this is not the thinking and scale that wins big.

That scale and thinking is, I think, is what differentiates successfull founders. Not alone, though, but combined with the capacity to execute.

Mentioning any of those qualities as differentiators is not unusual at all. Paul Graham wrote about “thinking big”, just as well as Fred Wilson and countless others. Calling founders “execution machines” is also pretty common. What I find most amazing is that those qualities are almost mutually exclusive, and hence so rare. Thinking big, as the authors above mention, is truly difficult.

There is a group that is inherently good at it — children. Here’s, for example, a project from Elif Bilgin, the last year’s global winner of Google Science Fair in her age category. Just think about it: a sixteen year old proposes a way to make plastics from banana peel. She most likely does not know about the political and economical intricacies of the chemical and agricultural industries, about how hard it is to bring a technology like this to a mass market, and about mind-blowingly complicated relationship between different parts of the Earth’s ecosystem. That’s great: all this does not restrain her imagination. You truly believe that you can change the world when you’re so young. This is thinking really big.

If you think you can do this too, try. It’s not that easy to let your imagination go. For every little project detail, your brain does a micro feasibility check, without you even noticing. The wilder your dreams are, the stronger is the pull to the ground.

It’s still possible to imagine a project like being born in the depths of, say, BASF, and given a green light. Then a person responsible for that would drown in the details. Local legislation, partner companies, manufacturing processes, keeping the eco groups at bay, etc. A really big checklist, meticulously followed may help. This is the startup’s execution part that may be less glamorous, but is always absolutely necessary.

Successful founders, I think, are those who can do both thinking big while keeping the execution complexity at bay. Their micro feasibility checks turn into a gut feeling about growing markets. Their execution capacity is big enough for so many variables involved in building of the startup. This is what makes them special.