Design

The following is funny, no doubt:

Design consists of creating things for clients who may not know what they want, until they see what you've done, then they know exactly what they want, but it's not what you did. [link]

But sure our clients know what they want, we just can't transfer that knowledge from their heads to ours in a form that is immediately consumable. There's only that much you can convey with words, boxes and arrows. The knowledge in its purest form just has to evolve over time. That's why constant communication is important — it is a transport for knowledge. (And that's why outsourced teams are at an inherent disadvantage.)