Explorers set out with a direction and the intent to reach the horizon - they don't have any other destination in mind than tomorrow's stretch of the journey and the final prize, the Source of the Nile. They don't have road maps or plans. They explore.
The day after tomorrow is an undiscovered country - it changes all the time right before our eyes. Experts are really good at telling us what will happen tomorrow (after all, they understand what happens today) but equally poor at guessing what happens the day after (something hitherto unforeseen has become the defining factor).
When designing new products, we should not think in terms of existing product plus, but define large challenges - double one performance, cut the weigh in half. Find a place on the horizon. The led the team explore - the only step that matters is the next step, there is no plan, because we don't know what we're going to find. In development, we don't know before hand what will turn out to be easy and what will remain intractable.
Working without a plan requires a strong sense of direction and mastery of today. Through solving today's problems we discover tomorrow's opportunities. In the end, the explorers reach the horizon because with small, non-aggressive teams, they pass through the lands they encounter without raising war-like reactions: they are no threat, they're passing through. It's hard for managers to live without a destination. They want to build bridges and then force everyone across. But how well does that work? Tomorrow might shift with the fog, but the horizon is still there, and so is the improvement direction. ONe step at a time in a steady direction gets you farther quicker than following the wrong plan.