Even the Simplest Thing Is Difficult

Everything is very simple in war, but the simplest thing is difficult.

Carl von Clausewitz, On War, Book I, Chapter VII, translated by J. J. Graham.

Clausewitz called the gap between war on paper and real war "friction": the small circumstances, uncertainties, and difficulties that accumulate when a plan meets reality.

I'm interested in what this says about product design. Not because building products is like going to war, but because the distinction between theory and practice feels familiar. A design can make sense on paper without being straightforward to build, use, or maintain.

Take something as simple as inviting someone to a workspace. Enter an email address, send an invitation, accept it, join. Four steps. The flow looks complete.

But the recipient already has an account under another email address. The invitation expires before they open it. The sender doesn't have permission to add people. Or the recipient understands how to accept, but not what they are being invited into.

None of these situations is particularly surprising. Together, they reveal how much the simple flow assumed.

The design was easy to describe because some of its operating conditions were left out.

This is where I think mastery becomes visible. It isn't only the ability to create a coherent model. It's recognising the difference between that model and reality, then knowing how to navigate it.

An experienced designer doesn't necessarily draw a more complicated diagram. They recognise which assumptions need testing, which exceptions could change the structure of the product, and which details can wait. They can distinguish a confusing interface from an interface exposing a deeper problem with permissions or ownership.

Theory still matters. We need models to reason about systems without holding every detail in our heads. But a model is useful partly because it leaves things out. Good judgment includes understanding the consequences of those omissions.

There is a trap here, too. "Reality is complicated" can become an excuse for a product that is unnecessarily difficult. Some friction can be removed. Some comes from conditions we need to design around. Learning to tell the difference is part of the work.

For me, the practical implication is to treat a design as a hypothesis about how something will work. When reality doesn't cooperate, the question isn't just how to get back to the original plan. It's what the difficulty reveals about the plan's assumptions.

Good design requires simplification. Mastery means knowing what that simplification hides.